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  • c-Si solar cells based on laser-processed dielectric films

     Martin Garcia, Isidro; Colina Brito, Monica Alejandra; Coll Valenti, Arnau; Lopez Rodriguez, Gema; Ortega Villasclaras, Pablo Rafael; Orpella Garcia, Alberto; Alcubilla Gonzalez, Ramon
    Energy procedia
    Vol. 55, p. 255-264
    DOI: 10.1016/j.egypro.2014.08.077
    Date of publication: 2014-09
    Journal article

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    This paper shows an innovative and low temperature fabrication technology for crystalline silicon (c-Si) solar cells where the highly-doped regions are punctually defined through laser processed dielectric films. Phosphorus-doped silicon carbide stacks (SiCx(n)) and aluminium oxide/silicon carbide (Al2O3/SiCx) stacks are used for the creation of n+ and p+ regions respectively. These films provide excellent surface passivation on both n- and p-type substrates with effective surface recombination velocity below 20 cm/s. Moreover, a wide laser parameter window for laser processing them leads to low recombination highly-doped regions that show emitter saturation current densities of 21 and 113 fA/cm2 for n+ and p+ emitters respectively. All this is combined in the DopLa (Doped by Laser) cell structure whose fabrication process can be reduced to wafer cleaning, film depositions, laser processing and metallization. As a proof of concept, 1x1 cm2 solar cells were finished on both p- and n-type substrates with promising results. The analysis of loss mechanisms shows that optical losses and technological issues in the translation of surface passivation from the solar cell precursors to the final device are limiting efficiency. Both are not inherent to DopLa structure and suggest room for improvement in these devices. On the other hand, the crucial role played by ohmic losses in the proposed structure is identified. These ohmic losses arise from the fact that both base contacts and emitter regions are defined in point-like patterns. Firstly, base contacts are defined in a 1 mm pitch square matrix introducing additional series resistance that can be reduced by using low resistivity substrates. Secondly, the emitter consists of laser processed local diffusions with an inversion layer emitter in-between characterized by very high sheet resistances. The ohmic losses introduced by this induced emitter are closely linked to the fixed charge density located at the dielectric/c-Si interface. As a result, we conclude that low resistivity n-type substrates fit better to DopLa cell concept because emitters are based on Al2O3/SiCx stacks which have higher fixed charge density, i.e. inversion layer emitters with lower sheet resistances, than their SiCx(n) counterparts.

    This paper shows an innovative and low temperature fabrication technology for crystalline silicon (c-Si) solar cells where the highly-doped regions are punctually defined through laser processed dielectric films. Phosphorus-doped silicon carbide stacks (SiCx(n)) and aluminium oxide/silicon carbide (Al2O3/SiCx) stacks are used for the creation of n+ and p+ regions respectively. These films provide excellent surface passivation on both n- and p-type substrates with effective surface recombination velocity below 20 cm/s. Moreover, a wide laser parameter window for laser processing them leads to low recombination highly-doped regions that show emitter saturation current densities of 21 and 113 fA/cm2 for n+ and p+ emitters respectively. All this is combined in the DopLa (Doped by Laser) cell structure whose fabrication process can be reduced to wafer cleaning, film depositions, laser processing and metallization. As a proof of concept, 1x1 cm2 solar cells were finished on both p- and n-type substrates with promising results. The analysis of loss mechanisms shows that optical losses and technological issues in the translation of surface passivation from the solar cell precursors to the final device are limiting efficiency. Both are not inherent to DopLa structure and suggest room for improvement in these devices. On the other hand, the crucial role played by ohmic losses in the proposed structure is identified. These ohmic losses arise from the fact that both base contacts and emitter regions are defined in point-like patterns. Firstly, base contacts are defined in a 1 mm pitch square matrix introducing additional series resistance that can be reduced by using low resistivity substrates. Secondly, the emitter consists of laser processed local diffusions with an inversion layer emitter in-between characterized by very high sheet resistances. The ohmic losses introduced by this induced emitter are closely linked to the fixed charge density located at the dielectric/c-Si interface. As a result, we conclude that low resistivity n-type substrates fit better to DopLa cell concept because emitters are based on Al2O3/SiCx stacks which have higher fixed charge density, i.e. inversion layer emitters with lower sheet resistances, than their SiCx(n) counterparts.

  • Rear contact pattern optimization based on 3D simulations for IBC solar cells with point-like doped contacts

     Carrió Díaz, David; Ortega Villasclaras, Pablo Rafael; Martin Garcia, Isidro; Lopez Rodriguez, Gema; Lopez Gonzalez, Juan Miguel; Orpella Garcia, Alberto; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    Energy procedia
    Vol. 55, p. 47-52
    DOI: 10.1016/j.egypro.2014.08.048
    Date of publication: 2014-09
    Journal article

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    In this work 3D simulations are used to study the impact of technological parameters on device performance of c-Si interdigitated back-contacted IBC solar cells with point-like doped contacts. In these cells, the highly-doped regions are defined in a point-like structure instead of the more classical arrangement of fully doped fingers. Numerical simulations allow us to optimize rear contact geometry, i.e. optimum pitch between contacts, depending on the substrate resistivity and the passivation quality of base contacts. Results show a trade-off between recombination and base resistive losses demonstrating limit efficiencies over 27% for a perfectly passivated structure on p- and n-type substrates. More realistic devices where state-of-the-art surface passivation is considered reach efficiencies beyond 22% on 2 +- 1 ohmcm substrates with optimum pitch values of 200 +- 50 µm.

  • High voltage ultrathin-photovoltaic minimodules: fabrication technology and application to bioimplantable telesupplying

     Bermejo Broto, Alexandra; Silvestre Berges, Santiago; Ortega Villasclaras, Pablo Rafael
    Microelectronic engineering
    Vol. 119, p. 109-114
    DOI: 10.1016/j.mee.2014.03.041
    Date of publication: 2014-05-01
    Journal article

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    In this work we show small (0.49 cm2) and thin (<70 µm) photovoltaic mini-generators capable of providing open circuit voltages up to 99 V and short circuit currents of 43 µA, achieving a maximum density power of 4.8 mW/cm2. The fabrication process and the thinning process of the minimodules are reported as well as its potential use in high voltage wearable or implantable applications. In this work we show the potential of this technology for high voltage low power consumption applications by means of a simulation study. The minimodules have been modeled using the well known one diode model and simulation results obtained using this model have been validated experimentally. An application example based on simulation for an implantable micropump low power consuming is shown. The system simulates real consumptions of 3 mW working at voltages of 90 Vpp (±45 V) and a frequency of 1 kHz. Simulation results show that the PV system formed by two minimodules allows the micropump system working for 3 h/day showing a good energy balance of the whole system.

  • Recovery of indium-tin-oxide/silicon heterojunction solar cells by thermal annealing

     Morales Vilches, Ana Belen; Voz Sanchez, Cristobal; Colina Brito, Monica Alejandra; Lopez Rodriguez, Gema; Martin Garcia, Isidro; Ortega Villasclaras, Pablo Rafael; Orpella Garcia, Alberto; Alcubilla Gonzalez, Ramon
    Energy procedia
    Vol. 44, p. 3-9
    DOI: 10.1016/j.egypro.2013.12.002
    Date of publication: 2014-01-31
    Journal article

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    The emitter of silicon heterojunction solar cells consists of very thin hydrogenated amorphous silicon layers deposited at low temperature. The high sheet resistance of this type of emitter requires a transparent conductive oxide layer, which also acts as an effective antireflection coating. The deposition of this front electrode, typically by Sputtering, involves a relatively high energy ion bombardment at the surface that could degrade the emitter quality. The work function of the transparent conductive oxide layer could also significantly modify the band structure at the emitter. In this work, we study the particular case of p-type crystalline silicon substrates with a stack of n-doped and intrinsic amorphous silicon layers deposited by Plasma-Enhanced Chemical Vapor Deposition. The front electrode was an indium-tin-oxide layer deposited by Sputtering. The Quasi-Steady- State Photoconductance technique has been used to characterize the emitter quality by measuring the effective lifetime and the implicit open-circuit voltage. These measurements confirmed a strong degradation of the heterojunction after depositing the indium-tin-oxide layer. However, it is also shown that the initial degradation could be completely recovered by an adequate thermal treatment. In this sense, annealing times from 10 to 90 minutes at temperatures ranging from 100 to 160 °C have been studied, both in vacuum and inside an oven.

    The emitter of silicon heterojunction solar cells consists of very thin hydrogenated amorphous silicon layers deposited at low temperature. The high sheet resistance of this type of emitter requires a transparent conductive oxide layer, which also acts as an effective antireflection coating. The deposition of this front electrode, typically by Sputtering, involves a relatively high energy ion bombardment at the surface that could degrade the emitter quality. The work function of the transparent conductive oxide layer could also significantly modify the band structure at the emitter. In this work, we study the particular case of p-type crystalline silicon substrates with a stack of n-doped and intrinsic amorphous silicon layers deposited by Plasma-Enhanced Chemical Vapor Deposition. The front electrode was an indium-tin-oxide layer deposited by Sputtering. The Quasi-Steady-State Photoconductance technique has been used to characterize the emitter quality by measuring the effective lifetime and the implicit open-circuit voltage. These measurements confirmed a strong degradation of the heterojunction after depositing the indium-tin-oxide layer. However, it is also shown that the initial degradation could be completely recovered by an adequate thermal treatment. In this sense, annealing times from 10 to 90 minutes at temperatures ranging from 100 to 160 ºC have been studied, both in vacuum and inside an oven.

  • Optimization of laser processes for local rear contacting of passivated silicon solar cells

     Colina Brito, Monica Alejandra; Martin Garcia, Isidro; Voz Sanchez, Cristobal; Morales Vilches, Ana Belen; Ortega Villasclaras, Pablo Rafael; Lopez Rodriguez, Gema; Garcia Molina, Francisco Miguel; Alcubilla Gonzalez, Ramon
    Energy procedia
    Vol. 44, p. 234-243
    DOI: 10.1016/j.egypro.2013.12.033
    Date of publication: 2014-01-31
    Journal article

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    Laser Firing Contact (LFC) and Laser Doping (LD) have become potential alternatives to the Al BSF thermal processing conventionally used in p-type c-Si solar cell rear contacts. Optimized LFC and LD processes allow, not only the generation of efficient micro-contacts, but also the diffusion of p-type doping impurities reducing the surface recombination velocity due to the formation of a local back surface field (BSF). In this work, three different laser strategies to create ohmic micro-contacts are studied: 1) evaporated Aluminum LFC, 2) Aluminum foil LFC and 3) Aluminum oxide (Al2O3) LD. The laser source used was a pulsed Nd-YAG 1064 nm laser working in the nanosecond regime. Laser parameters were explored to optimize the electrical behavior of the contacts and their carrier recombination rate. Optimized laser parameters lead to specific contact resistance in the 1.0 1.3 m¿¿cm2 range for all three strategies. From the point of view of carrier recombination, better results were obtained for Al2O3 LD, probably related to the lower energy pulse needed to create the contact. Next, the three proposed laser approaches were applied to the back surface of heterojunction silicon solar cells. Contact quality was not limiting any cell performance indicating that the contact quality is good enough to be applied in high-efficiency c-Si cell concepts. On the other hand, surface recombination velocity at the rear surface on the final devices also points out to Al2O3 LD as the best alternative.

    Laser Firing Contact (LFC) and Laser Doping (LD) have become potential alternatives to the Al BSF thermal processing conventionally used in p-type c-Si solar cell rear contacts. Optimized LFC and LD processes allow, not only the generation of efficient micro-contacts, but also the diffusion of p-type doping impurities reducing the surface recombination velocity due to the formation of a local back surface field (BSF). In this work, three different laser strategies to create ohmic micro-contacts are studied: 1) evaporated Aluminum LFC, 2) Aluminum foil LFC and 3) Aluminum oxide (Al2O3) LD. The laser source used was a pulsed Nd-YAG 1064 nm laser working in the nanosecond regime. Laser parameters were explored to optimize the electrical behavior of the contacts and their carrier recombination rate. Optimized laser parameters lead to specific contact resistance in the 1.0 - 1.3 mΩ·cm2 range for all three strategies. From the point of view of carrier recombination, better results were obtained for Al2O3 LD, probably related to the lower energy pulse needed to create the contact. Next, the three proposed laser approaches were applied to the back surface of heterojunction silicon solar cells. Contact quality was not limiting any cell performance indicating that the contact quality is good enough to be applied in high-efficiency c-Si cell concepts. On the other hand, surface recombination velocity at the rear surface on the final devices also points out to Al2O3 LD as the best alternative.

  • Grup de Recerca en Micro i Nanotecnologies (MNT)

     Alcubilla Gonzalez, Ramon; Puigdollers Gonzalez, Joaquin; Voz Sanchez, Cristobal; Rodriguez Martinez, Angel; Martin Garcia, Isidro; Bardes Llorensi, Daniel; Bermejo Broto, Alexandra; Calderer Cardona, Josep; Dominguez Pumar, Manuel M.; Prat Viñas, Luis; Garcies Salva, Pau; Jimenez Serres, Vicente; Lopez Gonzalez, Juan Miguel; Orpella Garcia, Alberto; Ortega Villasclaras, Pablo Rafael; Pons Nin, Joan; Silvestre Berges, Santiago; Garin Escriva, Moises; Colina Brito, Monica Alejandra; Morales Vilches, Ana Belen; Coll Valenti, Arnau; Lopez Rodriguez, Gema; Castañer Muñoz, Luis Maria
    Competitive project

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  • Células solares de silicio de alta eficiencia y bajo coste fabricadas a baja temperatura

     Lopez Gonzalez, Juan Miguel; Colina Brito, Monica Alejandra; Ortega Villasclaras, Pablo Rafael; Voz Sanchez, Cristobal
    Competitive project

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  • Photovoltaic and fuel cells in power MEMS for smart energy management

     García, Juan; Delgado, Francisco; Ortega Villasclaras, Pablo Rafael; Bermejo Broto, Alexandra
    Date of publication: 2014-01-01
    Book chapter

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  • Numerical simulations of rear point-contacted solar cells pn 2.2 Wcm p-type c-Si substrates

     Lopez Gonzalez, Juan Miguel; Martin Garcia, Isidro; Ortega Villasclaras, Pablo Rafael; Orpella Garcia, Alberto; Alcubilla Gonzalez, Ramon
    Progress in photovoltaics
    Vol. 2013
    DOI: 10.1002/pip.2399
    Date of publication: 2013-07
    Journal article

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    Rear surface of high-efficiency crystalline silicon solar cells is based on a combination of dielectric passivation and point-like contacts. In this work, we develop a 3D model for these devices based on 2.2¿Ocm p-type crystalline silicon substrates. We validate the model by comparison with experimental results allowing us to determine an optimum design for the rear pattern. Additionally, the 3D model results are compared with the ones deduced from a simpler and widely used 1D model. Although the maximum efficiency predicted by both models is approximately the same, large deviations are observed in open-circuit voltage and fill factor. 1D simulations overestimate open-circuit voltage because Dember and electrochemical potential drops are not taken into account. On the contrary, fill factor is underestimated because of higher ohmic losses along the base when 1D analytical model is used. These deviations are larger for relatively low-doped substrates, as the ones used in the experimental samples reported hereby, and poor passivated contacts. As a result, 1D models could mislead to too short optimum rear contact spacing.

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    Surface passivation and optical characterization of Al2O3/a-SiCx stacks on c-Si substrates  Open access

     Lopez Rodriguez, Gema; Ortega Villasclaras, Pablo Rafael; Voz Sanchez, Cristobal; Martin Garcia, Isidro; Colina Brito, Monica Alejandra; Morales Vilches, Ana Belen; Orpella Garcia, Alberto; Alcubilla Gonzalez, Ramon
    Beilstein Journal of Nanotechnology
    Vol. 4, p. 726-731
    DOI: 10.3762/bjnano.4.82
    Date of publication: 2013-11-06
    Journal article

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    The aim of this work is to study the surface passivation of aluminum oxide/amorphous silicon carbide (Al2O3/a-SiCx) stacks on both p-type and n-type crystalline silicon (c-Si) substrates as well as the optical characterization of these stacks. Al2O3 films of different thicknesses were deposited by thermal atomic layer deposition (ALD) at 200 °C and were complemented with a layer of a-SiCx deposited by plasma-enhanced chemical vapor deposition (PECVD) to form anti-reflection coating (ARC) stacks with a total thickness of 75 nm. A comparative study has been carried out on polished and randomly textured wafers. We have experimentally determined the optimum thickness of the stack for photovoltaic applications by minimizing the reflection losses over a wide wavelength range (300–1200 nm) without compromising the outstanding passivation properties of the Al2O3 films. The upper limit of the surface recombination velocity (Seff,max) was evaluated at a carrier injection level corresponding to 1-sun illumination, which led to values below 10 cm/s. Reflectance values below 2% were measured on textured samples over the wavelength range of 450–1000 nm.

  • An efficient fault diagnosis method for PV systems based on operating voltage-window

     Gokmen, Nuri; Karatepe, Engin; Silvestre Berges, Santiago; Celik, Berk; Ortega Villasclaras, Pablo Rafael
    Energy conversion and management
    Vol. 73, p. 350-360
    DOI: 10.1016/j.enconman.2013.05.015
    Date of publication: 2013-09
    Journal article

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    With the increasing use of photovoltaic (PV) systems, the research studies to improve the efficiency of PV systems have gained greater interest in recent years, especially under non-uniform operating conditions. However, there is a little attention on fault diagnosis of PV arrays. This paper develops and demonstrates a method that can efficiently detect the number of open and short circuit faults and discriminate between them and partial shading conditions. This method is based on only the measurement of operating voltage of PV string and ambient temperature. In that manner, the proposed method takes into consideration of the minimum number of sensors to reduce the cost of the system, as one of the main purposes of this study. The simulation and experimental results are presented to demonstrate the effectiveness of the proposed method under both uniform and non-uniform irradiance conditions.

  • Analysis of the dynamic short-circuit resistance in organic bulk-heterojunction solar cells: relation to the charge carrier collection efficiency

     Voz Sanchez, Cristobal; Puigdollers Gonzalez, Joaquin; Asensi López, José Miguel; Galindo Lorente, Sergi; Cheylan, S.; Pacios, R.; Ortega Villasclaras, Pablo Rafael; Alcubilla Gonzalez, Ramon
    Organic electronics
    Vol. 14, num. 6, p. 1643-1648
    DOI: 10.1016/j.orgel.2013.02.039
    Date of publication: 2013-06
    Journal article

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    This work studies the charge carrier collection efficiency in organic bulk-heterojunction solar cells based on polymer:fullerene blends. An equivalent circuit with a specific recombination term is proposed to describe the behavior of this type of devices. It is experimentally shown that this recombination term determines the slope of the current-voltage characteristic at the short-circuit condition. The variation of this dynamic resistance with the light intensity can be interpreted considering a dominant first-order recombination process. Finally, an analytical model under a constant electric field approximation is presented that can be used to calculate the charge carrier collection efficiency of the device. This model can be also used to estimate an effective mobility-lifetime product, which is characteristic of the quality of the active layer.

    This work studies the charge carrier collection efficiency in organic bulk-heterojunction solar cells based on polymer:fullerene blends. An equivalent circuit with a specific recombination term is proposed to describe the behavior of this type of devices. It is experimentally shown that this recombination term determines the slope of the current–voltage characteristic at the short-circuit condition. The variation of this dynamic resistance with the light intensity can be interpreted considering a dominant first-order recombination process. Finally, an analytical model under a constant electric field approximation is presented that can be used to calculate the charge carrier collection efficiency of the device. This model can be also used to estimate an effective mobility–lifetime product, which is characteristic of the quality of the active layer.

  • HIGH EFFICIENCY REAR CONTACT SOLAR CELLS AND ULTRA POWERFUL MODULES

     Alcubilla Gonzalez, Ramon; Ortega Villasclaras, Pablo Rafael; Lopez Gonzalez, Juan Miguel; Colina Brito, Monica Alejandra; Lopez Rodriguez, Gema; Martin Garcia, Isidro
    Competitive project

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  • High voltage ultrathin-photovoltaic minimodules: fabrication technology and application to bioimplantable telesupplying

     Bermejo Broto, Alexandra; Silvestre Berges, Santiago; Ortega Villasclaras, Pablo Rafael
    International Conference on Micro and Nano Engineering
    p. 459
    Presentation's date: 2013-09-17
    Presentation of work at congresses

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  • An IBC solar cell for the UPC CubeSat-1 mission

     Ortega Villasclaras, Pablo Rafael; Jove Casulleras, Roger; Pedret, A; Gonzalvez, G.; Lopez Rodriguez, Gema; Martin Garcia, Isidro; Dominguez Pumar, Manuel M.; Alcubilla Gonzalez, Ramon; Camps Carmona, Adriano Jose
    Spanish Conference on Electron Devices
    p. 333-336
    DOI: 10.1109/CDE.2013.6481410
    Presentation's date: 2013-02
    Presentation of work at congresses

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    In this work the fabrication and electrical characterization of interdigitated back contact IBC solar cells is shown. These solar cells have been specifically designed for a CubeSat based satellite under developement at the Universitat Politecnica de Catalunya (UPC). Solar cells incorporate a transparent cover-glass as an extraterrestrial radiation shield. Front surface passivation was achieved using an Al2O3 layer exhibiting surface recombination velocities 100 cmls at the final device. Measurements confirm photovoltaic efficiencies n's-12%, with open circuit voltages Voc's 650 m V and short circuit current densities Jsc's 25 mA/cm 2. A module with 11 IBC solar cells interconnected in series will be integrated in one of the faces of the satellite forming part of the power subsystem. Preliminary results confirm the good electrical performance of the module.

    In this work the fabrication and electrical characterization of interdigitated back contact IBC solar cells is shown. These solar cells have been specifically designed for a CubeSat based satellite under developement at the Universitat Politecnica de Catalunya (UPC). Solar cells incorporate a transparent cover-glass as an extraterrestrial radiation shield. Front surface passivation was achieved using an Al2O3 layer exhibiting surface recombination velocities <; 100 cmls at the final device. Measurements confirm photovoltaic efficiencies η's-12%, with open circuit voltages Voc's ~650 m V and short circuit current densities Jsc's ~25 mA/cm2. A module with 11 IBC solar cells interconnected in series will be integrated in one of the faces of the satellite forming part of the power subsystem. Preliminary results confirm the good electrical performance of the module.

  • Surface passivation and optical characterization of Al2O3/a-SiCx stacks on c-Si substrates

     López Martí, Gema; Ortega Villasclaras, Pablo Rafael; Voz Sanchez, Cristobal; Martin Garcia, Isidro; Colina Brito, Monica Alejandra; Morales Vilches, Ana Belen; Orpella Garcia, Alberto; Alcubilla Gonzalez, Ramon
    E-MRS Spring Meeting
    p. 1
    Presentation's date: 2013-05-27
    Presentation of work at congresses

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  • Boron diffused emitters passivated with Al2O3 films

     Masmitja Rusinyol, Gerard; Ortega Villasclaras, Pablo Rafael; Lopez Rodriguez, Gema; Calle Martin, Eric; Garcia Molina, Francisco Miguel; Martin Garcia, Isidro; Orpella Garcia, Alberto; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    Spanish Conference on Electron Devices
    p. 329-332
    DOI: 10.1109/CDE.2013.6481409
    Presentation's date: 2013
    Presentation of work at congresses

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    In this work we study the fabrication and characterization of boron diffused emitters using FZ c-Si(n) substrates. Emitter surface was passivated with Al2O3(25 nm thick) layers deposited by thermal atomic layer deposition ALD technique. This study covers a broad emitter sheet resistance Rsh range from 20 to 250 O/sq using both polished and textured wafers. Emitter electrical quality was tested by means of lifetime measurements using quasi-stationary photoconductance QSS-PC method. Dark saturation emitter current densities Joe's were extracted from lifetime measurements resulting in Joe's values ranging from 10 to 150 fA/cm2 depending on Rsh. These results are in the-state-of-the-art in boron emitter passivation.

    In this work we study the fabrication and characterization of boron diffused emitters using FZ c-Si(n) substrates. Emitter surface was passivated with Al2O3(25 nm thick) layers deposited by thermal atomic layer deposition ALD technique. This study covers a broad emitter sheet resistance Rsh range from 20 to 250 Ω/sq using both polished and textured wafers. Emitter electrical quality was tested by means of lifetime measurements using quasi-stationary photoconductance QSS-PC method. Dark saturation emitter current densities Joe's were extracted from lifetime measurements resulting in Joe's values ranging from 10 to 150 fA/cm2 depending on Rsh. These results are in the-state-of-the-art in boron emitter passivation.

  • Laser processing of Al2O3/a-SiCx:H stacks: a feasible solution for the rear surface of high-efficiency p-type c-Si solar cells

     Martin Garcia, Isidro; Ortega Villasclaras, Pablo Rafael; Colina Brito, Monica Alejandra; Orpella Garcia, Alberto; López Martí, Gema; Alcubilla Gonzalez, Ramon
    Progress in photovoltaics
    Vol. 21, num. 5, p. 1171-1175
    DOI: 10.1002/pip.2207
    Date of publication: 2013-08
    Journal article

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    We explore the potential of laser processing aluminium oxide (Al 2O3)/amorphous silicon carbide (a-SiCx:H) stacks to be used at the rear surface of p-type crystalline silicon (c-Si) solar cells. For this stack, excellent quality surface passivation is measured with effective surface recombination velocities as low as 2 cm/s. By means of an infrared laser, the dielectric film is locally opened. Simultaneously, part of the aluminium in the Al2O3 film is introduced into the c-Si, creating p+ regions that allow ohmic contacts with low-surface recombination velocities. At optimum pitch, high-efficiency solar cells are achievable for substrates of 0.5-2.5 O cm. Copyright © 2012 John Wiley & Sons, Ltd. We explore the potential of laser processing aluminium oxide (Al2O3)/amorphous silicon carbide (a-SiC x:H) stacks to be used at the rear surface of p-type crystalline silicon (c-Si) solar cells. For this stack, excellent quality surface passivation is measured with effective surface recombination velocities as low as 2 cm/s. By means of an infrared laser, part of the aluminium in the Al 2O3 film is introduced into the c-Si, creating p+ regions that allow ohmic contacts with low-surface recombination velocities.

    We explore the potential of laser processing aluminium oxide (Al2O3)/amorphous silicon carbide (a-SiCx:H) stacks to be used at the rear surface of p-type crystalline silicon (c-Si) solar cells. For this stack, excellent quality surface passivation is measured with effective surface recombination velocities as low as 2 cm/s. By means of an infrared laser, the dielectric film is locally opened. Simultaneously, part of the aluminium in the Al2O3 film is introduced into the c-Si, creating p+ regions that allow ohmic contacts with low-surface recombination velocities. At optimum pitch, high-efficiency solar cells are achievable for substrates of 0.5–2.5 Ω cm.

  • Impact of metallization techniques of surface passivation of high efficiency crystalline silicon solar cells

     Coll Valenti, Arnau; Martin Garcia, Isidro; Ortega Villasclaras, Pablo Rafael; Bermejo Broto, Alexandra; López Martí, Gema; Alcubilla Gonzalez, Ramon
    European Photovoltaic Solar Energy Conference and Exhibition
    p. 1213-1216
    DOI: 10.4229/28thEUPVSEC2013-2BV.2.1
    Presentation's date: 2013-10-02
    Presentation of work at congresses

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    Most of the high-efficiency c-Si solar cells are based on dielectric films that electrically passivate c-Si surface and must keep their passivation properties after metal deposition on top of them. This work studies the impact of three different aluminum Physical Vapor Deposition (PVD) methods (thermal, e-beam, sputtering) on the c-Si surface passivation provided by SiO2 and Al2O3 films. Effective surface recombination velocity is measured before and after metal deposition. Results show that e-beam and sputtering techniques degrade surface passivation while thermal evaporation has no impact. Surface passivation can be recovered and even improved by means of an annealing with the aluminum film on top of the dielectric leading to the so-called alnealing. Additionally, after this alnealing Capacitance-Voltage measurements and lifetime spectroscopy analysis suggest a strong dependence of fixed charge density for SiO2 films on the metal deposition technique that helps in c-Si surface passivation.

  • Silicon heterjunction for advanced rear contact cells: main results of the SHARCC project

     Desrues, T.; Martin Garcia, Isidro; de Vecchi, S.; Abolmasov, S.; Diouf, D.; Lukyanov, A.; Ortega Villasclaras, Pablo Rafael; Colina Brito, Monica Alejandra; Versavel, M.; Tuseau, M.; Souche, F.; Nychyporuk, T.; Gueunier-Farret, M.; Muñoz, D.; Lemiti, M.; Kleider, J.P.; Cabarrocas, P. Roca; Alcubilla Gonzalez, Ramon; Schlumberger, Y.; Ribeyron, P.J.
    European Photovoltaic Solar Energy Conference and Exhibition
    p. 1135-1138
    DOI: 10.4229/28thEUPVSEC2013-2BV.1.32
    Presentation's date: 2013-09-30
    Presentation of work at congresses

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    This paper presents the main results of a research project called SHARCC, focused on rear contacted silicon heterojunction solar cells. Within this project, funded by the French National Research Agency (ANR), different tasks were shared by the partners taking into account their specific skills. This project led to efficiencies about 19% on innovative cell structures obtained with an industrial process based on laser ablation. Keywords: silicon heterojunction, back contact

    This paper presents the main results of a research project called SHARCC, focused on rear contacted silicon heterojunction solar cells. Within this project, funded by the French National Research Agency (ANR), different tasks were shared by the partners taking into account their specific skills. This project led to efficiencies about 19% on innovative cell structures obtained with an industrial process based on laser ablation.

  • SENSOSOL: MultiFOV 4-Quadrant high precision sun sensor for satellite attitude control

     Delgado, Francisco J.; Quero Reboul, Jose Manuel; Garcia Ortega, Juan; López Tarrida, Cristina; Moreno, José M.; Sáez, Agustín G.; Ortega Villasclaras, Pablo Rafael
    Spanish Conference on Electron Devices
    p. 1-4
    DOI: 10.1109/CDE.2013.6481358
    Presentation's date: 2013-02-13
    Presentation of work at congresses

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    The design, manufacturing and calibration of an improved miniaturized two axis sun sensor for satellite attitude control will be shown. The high precision is obtained by the subdivision of the field of view (FOV). The FOV and the resolution obtained are ±60° and 0.5° for the coarse measure and ±6° with precision better than 0.05° for the fine measure.

  • Recovery of indium-tin-oxide/silicon heterojunction solar cells by thermal annealing

     Morales Vilches, Ana Belen; Voz Sanchez, Cristobal; Colina Brito, Monica Alejandra; López Martí, Gema; Martin Garcia, Isidro; Ortega Villasclaras, Pablo Rafael; Orpella Garcia, Alberto; Alcubilla Gonzalez, Ramon
    E-MRS Spring Meeting
    p. D.PI. 20
    Presentation's date: 2013-05-27
    Presentation of work at congresses

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  • 3D simulations of back-contact back-junction c-Si(P) solar cells with doped point contacts

     Carrió Díaz, David; Ortega Villasclaras, Pablo Rafael; López Martí, Gema; Lopez Gonzalez, Juan Miguel; Martin Garcia, Isidro; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    European Photovoltaic Solar Energy Conference and Exhibition
    p. 1607-1610
    DOI: 10.4229/28thEUPVSEC2013-2CV.3.44
    Presentation's date: 2013-10-02
    Presentation of work at congresses

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    The back-contact back-junction BC-BJ solar cell concept is a promising photovoltaic structure for both laboratory and industrial c-Si solar cells. High efficiency devices based on this concept have been reported in the past using either diffused regions or applying the heterojunction with intrinsic thin layer HIT concept to perform both base and emitter contacts. In this work we use 3D numerical simulations to study the impact of technological parameters on device performance of c-Si(p) BC-BJ solar cells with point-like doped contacts. Numerical simulations allow us to optimize rear contact geometry as a trade-off between recombination and base resistive losses, leading to photovoltaic efficiencies higher than 18.3% and up to 22.3% on 2.2 ¿cm FZ substrates depending on the back contact pattern and the passivation quality of base contacts.

    The back-contact back-junction BC-BJ solar cell concept is a promising photovoltaic structure for both laboratory and industrial c-Si solar cells. High efficiency devices based on this concept have been reported in the past using either diffused regions or applying the heterojunction with intrinsic thin layer HIT concept to perform both base and emitter contacts. In this work we use 3D numerical simulations to study the impact of technological parameters on device performance of c-Si(p) BC-BJ solar cells with point-like doped contacts. Numerical simulations allow us to optimize rear contact geometry as a trade-off between recombination and base resistive losses, leading to photovoltaic efficiencies higher than 18.3% and up to 22.3% on 2.2 cm FZ substrates depending on the back contact pattern and the passivation quality of base contacts.

  • Optimization of laser micro-doping processes for silicon photovoltaic applications

     Colina Brito, Monica Alejandra; Martin Garcia, Isidro; Voz Sanchez, Cristobal; Morales Vilches, Ana Belen; Ortega Villasclaras, Pablo Rafael; López Martí, Gema; Garcia Molina, Francisco Miguel; Orpella Garcia, Alberto; Muñoz Martín, D.; Sánchez Aniorte, M. Isabel; Molpeceres Alvarez, Carlos; Alcubilla Gonzalez, Ramon
    E-MRS Spring Meeting
    p. D.PI. 31
    Presentation's date: 2013-05-27
    Presentation of work at congresses

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  • 27th EU PVSEC Poster Award

     Colina Brito, Monica Alejandra; Voz Sanchez, Cristobal; Martin Garcia, Isidro; Alcubilla Gonzalez, Ramon; Ortega Villasclaras, Pablo Rafael; Lopez Rodriguez, Gema; Morales Vilches, Ana Belen; Sánchez Aniorte, M. Isabel; Molpeceres Alvarez, Carlos
    Award or recognition

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  • Laser-fired contact optimization in c-Si solar cells

     Ortega Villasclaras, Pablo Rafael; Orpella Garcia, Alberto; Martin Garcia, Isidro; Colina Brito, Monica Alejandra; Lopez Rodriguez, Gema; Voz Sanchez, Cristobal; Sánchez, Isabel; Molpeceres Alvarez, Carlos; Alcubilla Gonzalez, Ramon
    Progress in photovoltaics
    Vol. 20, num. 2, p. 173-180
    DOI: 10.1002/pip.1115
    Date of publication: 2012-03
    Journal article

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    In this work we study the optimization of laser-fired contact (LFC) processing parameters, namely laser power and number of pulses, based on the electrical resistance measurement of an aluminum single LFC point. LFC process has been made through four passivation layers that are typically used in c-Si and mc-Si solar cell fabrication: thermally grown silicon oxide (SiO2), deposited phosphorus-doped amorphous silicon carbide (a-SiCx/H(n)), aluminum oxide (Al2O3) and silicon nitride (SiNx/H) films. Values for the LFC resistance normalized by the laser spot area in the range of 0.65–3 mΩ cm2 have been obtained.

  • P-type c-Si solar cells based on rear side laser processing of Al 2O 3/SiC x stacks

     Ortega Villasclaras, Pablo Rafael; Martin Garcia, Isidro; Lopez Rodriguez, Gema; Colina Brito, Monica Alejandra; Orpella Garcia, Alberto; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    Solar energy materials and solar cells
    Vol. 106, p. 80-83
    DOI: 10.1016/j.solmat.2012.05.012
    Date of publication: 2012-11
    Journal article

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  • Influence of wavelength on laser doping and laser-fired contact processes for c-Si solar cells

     Molpeceres Alvarez, Carlos; Sanchez Aniorte, Maria Isabel; Morales Furio, Miguel; Muñoz, David; Martin Garcia, Isidro; Ortega Villasclaras, Pablo Rafael; Colina Brito, Monica Alejandra; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    SPIE Optics+Photonics
    p. 847308-1-847308-11
    DOI: doi: 10.1117/12.929456
    Presentation's date: 2012-08-15
    Presentation of work at congresses

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    This work investigates the influence of the laser wavelength on laser doping (LD) and laser - fired contact (LFC) formation in solar cell structures . We compare the results obtained using the three first harmonics (corresponding to wavelengths of 1064 nm, 532 nm and 355 nm) of fully commercial solid state laser sources with pulse width in the ns range. The discussion is based on the impact on the morphology and electrical characteristics of test structures. In the case of LFC the study includes th e influence of different passivation layers and the assessment of the process quality through electrical resistance measurements of an alumin i um single LFC point for the different wavelengths. Values for the normalized LFC resistance far below 1 .0 m Ω cm 2 have been obtained, with better results at s horter wavelen g ths. To assess the influence of the laser wavelength on LD we have created n+ regions into p - type c - Si wafers , using a dry LD approach to define punctual emitters. J - V characteristics show exponen tial trends at mid - injection for a broad parametric window in all wavelengths, with local ideality factors well below 1.5. In bot h processes the best results have been obtained using green (532 nm) and , specially, UV (355 nm) . This indicates that to minim ize the thermal damage in the material is a clear requisite to obtain th e best electrical performance, thus indicating that UV laser shows better potential to be used in high efficiency solar cells.

  • Optimization of al2o3 films obtained by ald to passivate p-type c-silicon wafers

     Lopez Rodriguez, Gema; Ortega Villasclaras, Pablo Rafael; Martin Garcia, Isidro; Colina Brito, Monica Alejandra; Orpella Garcia, Alberto; Alcubilla Gonzalez, Ramon
    European Photovoltaic Solar Energy Conference and Exhibition
    p. 1692-1695
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Influence of laser wavelength on laser-fired contacts for crystalline silicon solar cells

     Sanchez Aniorte, Maria Isabel; Muñoz Martín, D.; Morales Furio, Miguel; Ortega Villasclaras, Pablo Rafael; Martin Garcia, Isidro; Colina Brito, Monica Alejandra; Alcubilla Gonzalez, Ramon; Molpeceres Alvarez, Carlos
    European Photovoltaic Solar Energy Conference and Exhibition
    p. 1688-1691
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Accurate and wide-field-of-view MEMS-based sun sensor for industrial applications

     Delgado, Francisco J.; Quero, J.M.; Garcia Ortega, Juan; López Tarrida, Cristina; Ortega Villasclaras, Pablo Rafael; Bermejo Broto, Alexandra
    IEEE transactions on industrial electronics
    Vol. 59, num. 12, p. 4871-4880
    DOI: 10.1109/TIE.2012.2188872
    Date of publication: 2012-12
    Journal article

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    This paper describes the design, fabrication, simulation, and experimental results of an improved miniaturized two-axis sun sensor for industrial applications, created by adapting a technology used previously in satellite applications. The sensor for each axis is composed of six photodiodes integrated in a crystalline silicon substrate, and a layer of cover glass, which is used to protect the silicon and to hold the windows. The high precision is obtained by the subdivision of the field of view (FOV), which is ±60º, with a resolution of 0.1º. Each region is controlled by an independent high precision solar sensor. The sensor can be used for sun tracking applications in photovoltaic system, heliostat concentration plants and lighting applications.

  • Optimization of laser doping processes for the creation of p+ regions from solid dopant sources

     Colina Brito, Monica Alejandra; Martin Garcia, Isidro; Voz Sanchez, Cristobal; Morales Vilches, Ana Belen; Ortega Villasclaras, Pablo Rafael; Lopez Rodriguez, Gema; Orpella Garcia, Alberto; Alcubilla Gonzalez, Ramon; Sánchez Aniorte, M. Isabel; Molpeceres Alvarez, Carlos
    European Photovoltaic Solar Energy Conference and Exhibition
    p. 1885-1889
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Light harvesting photovoltaic mini-generator

     Bermejo Broto, Alexandra; Silvestre Berges, Santiago; Ortega Villasclaras, Pablo Rafael; Herrera, Gerard
    Progress in photovoltaics
    num. 2011, p. 1-8
    DOI: 10.1002/pip.1162
    Date of publication: 2011-08-23
    Journal article

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  • Células fotovoltaicas con un rendimiento del 20.5%

     Ortega Villasclaras, Pablo Rafael; Lopez Rodriguez, Gema; Orpella Garcia, Alberto; Martin Garcia, Isidro; Colina Brito, Monica Alejandra; Voz Sanchez, Cristobal; Bermejo Broto, Alexandra; Puigdollers Gonzalez, Joaquin; Garcia Molina, Francisco Miguel; Alcubilla Gonzalez, Ramon
    Solar News
    num. 32, p. 40-43
    Date of publication: 2011-03-01
    Journal article

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    Un grupo de investigadores de la Universitat Politècnica de Catalunya (UPC) han desarrollado un proceso de fabricación que permite obtener rendimientos de conversión fotovoltaicos del 20,5%. Esto supone una mejora sustancial con respecto a los rendimientos habituales en células comerciales que sitúa en un 15%, y la cuota más elevada a la que se ha llegado hasta ahora en España. En estos momentos trabajan en mejoras que las hagan accesibles industrialmente. El avance, tras años de investigación, consiste en minimizar los diferentes mecanismos de pérdidas que influyen en el cómputo de la eficiencia de conversión fotovoltaica.

  • Access to the full text
    Towards photovoltaic powered artificial retina  Open access

     Silvestre Berges, Santiago; Bermejo Broto, Alexandra; Guasch Murillo, Daniel; Ortega Villasclaras, Pablo Rafael; Castañer Muñoz, Luis Maria
    Journal of Accessibility and Design for All
    Vol. 1, num. 1, p. 3-11
    Date of publication: 2011
    Journal article

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    The aim of this article is to provide an overview of current and future concepts in the field of retinal prostheses, and is focused on the power supply based on solar energy conversion; we introduce the possibility of using PV minimodules as power supply for a new concept of retinal prostheses: Photovoltaic Powered Artificial Retina (PVAR). Main characteristics of these PV modules are presented showing its potential for this application.

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    Crystalline silicon solar cells beyond 20% efficiency  Open access

     Ortega Villasclaras, Pablo Rafael; Lopez Rodriguez, Gema; Orpella Garcia, Alberto; Colina Brito, Monica Alejandra; Martin Garcia, Isidro; Voz Sanchez, Cristobal; Bermejo Broto, Alexandra; Puigdollers Gonzalez, Joaquin; Garcia Molina, Miguel; Alcubilla Gonzalez, Ramon
    Spanish Conference on Electron Devices
    p. 1-4
    Presentation's date: 2011-02-08
    Presentation of work at congresses

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    —This paper describes a fabrication process to obtain high efficiency c-Si cells (> 20%) based on the Laser Fired Contact Passivated Emitter Rear Cell (LFC-PERC) concept. Photovoltaic efficiencies beyond 20% have been achieved using thermal SiO2 as a rear passivation layer on 2 cm x 2 cm solar cells with 0.45 cm Fz c-Si substrates. Efficiencies up to 22% are expected for material resistivities in the 0.4–5 cm using an optimized rear contact grid

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    A miniaturized two axis sun sensor for attitude control of nano-satellites  Open access

     Ortega Villasclaras, Pablo Rafael; Lopez Rodriguez, Gema; Ricart Campos, Jordi; Dominguez Pumar, Manuel M.; Castañer Muñoz, Luis Maria; Quero, J.M.; Tarrida, C. L.; Reina, M.; Gras, Ana; Angulo, M.
    IEEE sensors journal
    Vol. 10, num. 10, p. 1623-1632
    DOI: 10.1109/JSEN.2010.2047104
    Date of publication: 2010-10-10
    Journal article

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    This paper describes the design, fabrication, characterization, and satellite integration of a miniaturized two axis sun sensor which has been used in the attitude control system of the Spanish nano-satellite NANOSAT-1B. This device is made of four silicon photodiodes monolithically integrated in a crystalline silicon substrate, protected by a transparent cover glass assembled on the same silicon die against space radiation damage. The sensor fabrication combines standard silicon processing technology with a high performance solar cell fabrication process. The sensor, including electronics and mechanical and electrical interfacing with the satellite, has a small size (3 cm 3 cm) and low weight (24 gr.), with a sun field-of-view greater than with an angle accuracy better than 0.15 . Three of these sensors have already been integrated in the NANOSAT-1B platform that has been successfully launched in July 2009.

  • INNDISOL

     Alcubilla Gonzalez, Ramon; Martin Garcia, Isidro; Ortega Villasclaras, Pablo Rafael; Orpella Garcia, Alberto; Puigdollers Gonzalez, Joaquin; Voz Sanchez, Cristobal
    Competitive project

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  • Nanophotonics for Energy Efficiency

     Voz Sanchez, Cristobal; Ortega Villasclaras, Pablo Rafael; Martin Garcia, Isidro; Orpella Garcia, Alberto; Puigdollers Gonzalez, Joaquin; Bermejo Broto, Alexandra; Alcubilla Gonzalez, Ramon
    Competitive project

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  • A new design of high precision solar microsensor for satellite aplications

     Delgado, Francisco J.; Ortega Villasclaras, Pablo Rafael; Lopez Tarrida, Cristina; Garcia Ortega, Juan; Angulo, Manuel; Quero Reboul, Jose Manuel
    Annual IEEE Conference on Sensors
    p. 552-556
    DOI: 10.1109/ICSENS.2010.5690486
    Presentation's date: 2010-04-01
    Presentation of work at congresses

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    This paper shows the design and calibration of an improved miniaturized two-axis sun sensor for satellite attitude control. The proposed new structure is based on a previous sun sensor structure by adding multiple sensing cells. The improvement in precision is obtained by the subdivision of field of view (FoV), which is expected to be ±60°, with a resolution of 0.1°. In the paper, both the mathematical model and the experimental results are presented. The resulting device will be incorporated in Microsat satellite from INTA, which will be launched in 2012.

  • Optimization of the rear point contact scheme of crystalline silicon solar cells using laser-fired contacts

     Ortega Villasclaras, Pablo Rafael; Orpella Garcia, Alberto; López, Gema; Martin Garcia, Isidro; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon; Colina Brito, Monica Alejandra; Sánchez Aniorte, M. Isabel; Perales, Francisco; Molpeceres Alvarez, Carlos
    European Photovoltaic Solar Energy Conference and Exhibition
    p. 2126-2129
    DOI: ISBN 3-936338-26-4
    Presentation's date: 2010-09-06
    Presentation of work at congresses

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    This paper is focused on the optimization of the rear contact scheme of p-type c-Si LFC-PERC high efficiency solar cells minimizing base ohmic losses without jeopardize rear passivation. This is carried out optimizing on one hand the LFC laser conditions for minimum point resistance and on the other hand through a proper design of the contact grid layout finding the optimum trade off for a given base resistivity between rear passivation and base resistance. LFC process was carried out through 110 nm thermal SiO2 passivation layer using IR and green lasers. Very low specific contact resistances, 0.1 mcm2 have been achieved independently of the laser used. For optimum rear contacted area fraction efficiencies over 21.5% and 22%, for IR and green lasers respectively are expected in the 0.5-5 cm resistivity range.

  • Tecnología de semiconductores orgánicos: fabricación de dispositivos electrónicos en aulas docentes

     Puigdollers Gonzalez, Joaquin; Voz Sanchez, Cristobal; Ortega Villasclaras, Pablo Rafael; Martin Garcia, Isidro
    IEEE - RITA (Revista iberoamericana de tecnologías del aprendizaje)
    Vol. 4, num. 1, p. 69-74
    Date of publication: 2009-02
    Journal article

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  • DESARROLLO DE UN MICROSENSOR SOLAR DE ALTA PRECISIÓN uFINE-SENSOR PARA EL SATÉLITE INTAuSAT

     Bermejo Broto, Alexandra; Ortega Villasclaras, Pablo Rafael
    Competitive project

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  • Comparison of bulk micromachined high voltage light scavenger

     Bermejo Broto, Alexandra; Ortega Villasclaras, Pablo Rafael; Castañer Muñoz, Luis Maria
    Spanish Conference on Electron Devices
    p. 91-93
    Presentation's date: 2009-02
    Presentation of work at congresses

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    c-Si photovoltaic arrays  Open access

     Bermejo Broto, Alexandra; Ortega Villasclaras, Pablo Rafael; Castañer Muñoz, Luis Maria
    Anual Meeting of the IEEE Photonics Society
    p. 119-120
    Presentation of work at congresses

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    Crystalline silicon small photovoltaic arrays are shown. Electrical isolation of individual cells and series connection between them to integrate series arrays are discussed. High open circuit voltage values in the range of 100 V and power densities of 7.2 mW/cm2 have been achieved.

  • Advances in a baseline process towards high efficiency c-Si solar cell fabrication

     Ortega Villasclaras, Pablo Rafael; Lopez, G.; Martin Garcia, Isidro; Bermejo Broto, Alexandra; Blanqué, Servane; Garcia Molina, Miguel; Orpella Garcia, Alberto; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    Spanish Conference on Electron Devices
    p. 349-352
    Presentation's date: 2009-02-12
    Presentation of work at congresses

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  • Determination of the Density of States in N-type organic Thin-Film Transistors

     Puigdollers Gonzalez, Joaquin; Ortega Villasclaras, Pablo Rafael; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    International Thin Film Transistor Conference
    p. 117-120
    Presentation of work at congresses

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  • MEMS solar sensor testing for satellite applications

     García Ortega, J.; Tarrida, C. L.; Quero, J.M.; Delgado, F.J.; Ortega Villasclaras, Pablo Rafael; Castañer Muñoz, Luis Maria; Reina, M.; Angulo, M.; Morilla, Y.; García López, J.
    Spanish Conference on Electron Devices
    p. 345-348
    Presentation of work at congresses

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  • Claves científicas para el desarrollo de dispositivos fotovoltaicos avanzados de silicio en lámina delgada comerciales (CLASICO)

     Calderer Cardona, Josep; Voz Sanchez, Cristobal; Bermejo Broto, Alexandra; Ortega Villasclaras, Pablo Rafael
    Competitive project

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  • Optocoupler driving of MEMS electrostatic switches

     Bermejo Broto, Alexandra; Molinero Giles, David; Ortega Villasclaras, Pablo Rafael; Castañer Muñoz, Luis Maria
    Journal of micromechanics and microengineering
    Vol. 18, num. 5
    Date of publication: 2008-05
    Journal article

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