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  • 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
    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.

  • Restraints in low dimensional organic semiconductor devices at high current densities

     Pfattner, Raphael; Moreno Sierra, Cesar; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon; Rovira, Concepció; Puigdollers Gonzalez, Joaquin; Mas Torrent, Marta
    Organic electronics
    Date of publication: 2014-01
    Journal article

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    The understanding of the charge carrier transport in electronic materials is of crucial interest for the design of efficient devices including especially the restraints that arise from device miniaturization. In this work the performance of organic thin-film and single crystal field-effect transistors with the same active material was studied in detail focusing on the high current density regime, where a pronounced non-hysteretic maximum in the transconductance was found. Interestingly, in this operation mode for both, thin films and single crystals, comparable densities of free and gate-induced charge carriers were estimated. Kelvin probe microscopy was used to measure the contact potential difference and the electrical field along the transistor channel during device operation exhibiting the formation of local space charges in the high current density regime. © 2013 Elsevier B.V. All rights reserved.

  • 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
    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.

  • Compositional influence on the electrical performance of zinc indium tin oxide transparent thin-film transistors

     Marsal Vinade, Albert; Carreras Seguí, Paz; Puigdollers Gonzalez, Joaquin; Voz Sanchez, Cristobal; Galindo Lorente, Sergi; Alcubilla Gonzalez, Ramon; Bertomeu Balaguero, Joan; Antony, Aldrin
    Thin solid films
    Date of publication: 2014-03-31
    Journal article

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    In this work, zinc indium tin oxide layers with different compositions are used as the active layer of thin film transistors. This multicomponent transparent conductive oxide is gaining great interest due to its reduced content of the scarce indium element. Experimental data indicate that the incorporation of zinc promotes the creation of oxygen vacancies, which results in a higher free carrier density. In thin-film transistors this effect leads to a higher off current and threshold voltage values. The field-effect mobility is also strongly degraded, probably due to coulomb scattering by ionized defects. A post deposition annealing in air reduces the density of oxygen vacancies and improves the field-effect mobility by orders of magnitude. Finally, the electrical characteristics of the fabricated thin-film transistors have been analyzed to estimate the density of states in the gap of the active layers. These measurements reveal a clear peak located at 0.3 eV from the conduction band edge that could be attributed to oxygen vacancies. (C) 2013 Elsevier B.V. All rights reserved.

  • 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
    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.

  • 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
    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.

  • Progress in silicon heterojunction solar cell fabrication with rear laser-fired contacts

     Morales Vilches, Ana Belen; Voz Sanchez, Cristobal; Colina Brito, Monica Alejandra; Lopez Rodriguez, Gema; Martin Garcia, Isidro; Orpella Garcia, Alberto; Puigdollers Gonzalez, Joaquin; Garcia Rodriguez, Miguel; Alcubilla Gonzalez, Ramon
    Spanish Conference on Electron Devices
    Presentation's date: 2013-02
    Presentation of work at congresses

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    Silicon Heterojunction (SHJ) solar cells are one of the most promising alternatives for high efficiency industrially feasible solar cells. The structure of these devices is based on hydrogenated amorphous silicon (a-Si:H) layers deposited at low temperature on crystalline silicon (c-Si) substrates. This fabrication process reduces the thermal stress on the substrate and is compatible with thinner wafers. In this work, we present our recent progress in the fabrication of SHJ solar cells on p-type c-Si wafers. The deposition conditions of hydrogenated amorphous silicon-carbon (a-SiCx:H) layers obtained by Plasma Enhanced Chemical Vapor Deposition (PECVD) are optimized. We have also applied a novel laser-firing process to contact the rear side of the fabricated devices. In this way, solar cells with point contacts through rear passivating layers can be fabricated without any photolithographic step.

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

     Carrió, D.; Ortega Villasclaras, Pablo Rafael; López, Gema; Lopez Gonzalez, Juan Miguel; Martin Garcia, Isidro; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    European Photovoltaic Solar Energy Conference and Exhibition
    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.

  • Células solares de heterounión de silicio: alta eficiencia en procesos de fabricación a baja temperatura

     Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    Revista española de física
    Date of publication: 2013-02
    Journal article

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    Las células de heterounión de silicio se basan en uniones formadas entre sustratos de silicio cristalino y capas de silicio amorfo hidrogenado depositadas a baja temperatura. El proceso de fabricación de estos dispositivos reduce el estrés térmico sobre los sustratos, lo que resulta más adecuado para la utilización de obleas más delgadas. Por tanto, esta tecnología aparece como una interesante alternativa a las tradicionales uniones pn de silicio obtenidas en procesos de difusión a alta temperatura. Las células de heterounión de silicio ya han alcanzado altas eficiencias, tanto a escala de laboratorio como en procesos de producción industrial. Actualmente, esta tecnología se está combinando con nuevos procesos de fabricación asistidos por láser a la vez que se desarrollan nuevas estructuras de célula solar.

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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
    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.

  • 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
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Low recombination n+ regions created by n+ c-Si epitaxial layers and laser processing of phosphorus-doped SiCx films

     Martin Garcia, Isidro; Colina Brito, Monica Alejandra; Orpella Garcia, Alberto; Voz Sanchez, Cristobal; De Vecchi, S.; Desrues, T.; Abolmasov, S.; Roca i Cabarrocas, P.; Alcubilla Gonzalez, Ramon
    European Photovoltaic Solar Energy Conference and Exhibition
    Presentation's date: 2012-09
    Presentation of work at congresses

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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
    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.

  • Lumogen violet dye as luminiscent down-shifting layer for C-silicon solar cells

     Ahmed, H.; Kennedy, M.; Confrey, T.; Doran, J.; McCormack, S.J.; Galindo Lorente, Sergi; Voz Sanchez, Cristobal; Puigdollers Gonzalez, Joaquin
    European Photovoltaic Solar Energy Conference and Exhibition
    Presentation's date: 2012-09-25
    Presentation of work at congresses

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    In this investigation Naphtalimide based Lumogen Violet organic dye [BASF] is characterized for inclusion in luminescent downshifting (LDS) layers. A PV device made up of an LDS layer of Lumogen Violet deposited on top of a crystalline silicon cell has been fabricated to improve its power conversion efficiency. External quantum efficiency measurements and outdoor tests for the PV/LDS devices are discussed. An analytical model was also developed to compare experiment results with the model predictions.

  • 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
    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.

  • Comparison between the density-of-states of picene transistors measured in air and under vacuum

     Voz Sanchez, Cristobal; Marsal Vinade, Albert; Moreno Sierra, Cesar; Puigdollers Gonzalez, Joaquin; Alcubilla Gonzalez, Ramon
    Synthetic metals
    Date of publication: 2012-01
    Journal article

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    Picene has recently attracted much attention as the active layer in organic thin-film transistors because of its good performance in air. In this work, we have fabricated picene thin-film transistors that exhibit field-effect mobilities up to 1.3 cm2 V−1 s−1 and on/off ratios above 105 in ambient conditions. These devices have been electrically characterized over the temperature range 300–360 K in air and also under vacuum conditions. In particular, the thermal activation energy of the channel conductance as a function of the gate bias has been measured. The dependence of the activation energy on the gate bias corresponds to a gradual shift of the Fermi level towards the HOMO level as more gap states are filled by trapped holes. The density-of-states can be estimated from the derivative of the activation energy with respect to gate bias. The calculated density-of-states is compared for devices measured in air and under vacuum conditions. These results can help to understand the gas sensing capability of picene, together with its enhanced electrical performance after air exposure.

  • 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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  • 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
    Date of publication: 2012-11
    Journal article

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  • Método para el dopado selectivo de un semiconductor mediante transferencia inducida por láser

     Colina Brito, Monica Alejandra; Voz Sanchez, Cristobal; Martin Garcia, Isidro; Alcubilla Gonzalez, Ramon; Molpeceres Alvarez, Carlos; Sanchez Aniorte, Maria Isabel
    Date of request: 2012-07-06
    Invention patent

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    Método para el dopado selectivo de un semiconductor mediante transferencia inducida por láser, que comprende un sistema precursor (200) compuesto de al menos una capa absorbente (202) a la radiación láser, con una solución dopante (203) y un soporte transparente (201) , el cual se coloca enfrentado y en contacto directo con el sistema receptor (300) donde se integra el substrato (301) semiconductor y se irradia con uno o más pulsos de un haz láser (100) focalizados en la interfaz entre la fuente y el substrato, provocando la transferencia de material proveniente de la fuente hacia el substrato y la introducción de átomos dopantes provenientes de la fuente dentro del substrato semiconductor. El sustrato (301) es, preferentemente, una oblea de silicio con una cara frontal (302) y una cara posterior (303) con capas pasivante antirreflejo dieléctricas.

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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
    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

  • Low voltage operating complementary inverters fabricated at low temperature

     Puigdollers Gonzalez, Joaquin; Marsal Vinade, Albert; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    Spanish Conference on Electron Devices
    Presentation's date: 2011-02-09
    Presentation of work at congresses

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  • Avances en materiales e interfaces para células solares de silicio en lámina delgada

     Voz Sanchez, Cristobal
    Participation in a competitive project

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  • Q-00012

     Voz Sanchez, Cristobal; Puigdollers Gonzalez, Joaquin
    Participation in a competitive project

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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
    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.

  • Density-of-states in pentacene from the electrical characteristics of thin-film transistors

     Puigdollers Gonzalez, Joaquin; Marsal Vinade, Albert; Cheylan, S.; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    Organic electronics
    Date of publication: 2010-08
    Journal article

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  • 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
    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.

  • Surface recombination analysis in silicon-heterojunction solar cells

     Barrio, Rocío; Gandía, J.J; Cárabe, J.; González, N.; Torres, I.; Muñoz, D.; Voz Sanchez, Cristobal
    Solar energy materials and solar cells
    Date of publication: 2010-02
    Journal article

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  • Oxidos metálicos nanoestructurados y substratos nanotexturados para células solares orgánicas

     Alcubilla Gonzalez, Ramon; Voz Sanchez, Cristobal; Puigdollers Gonzalez, Joaquin
    Participation in a competitive project

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  • INNDISOL

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

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  • Nanophotonics for Energy Efficiency

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

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  • Development of LASER fired contacts on silicon heterojunction solar cells for the application to rear contact structures

     Orpella Garcia, Alberto; Martin Garcia, Isidro; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    Physica status solidi C. Current topics in solid state physics
    Date of publication: 2010
    Journal article

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  • Development of laser-fired contacts for amorphous silicon layers obtained by Hot-Wire CVD

     Munoz, D; Voz Sanchez, Cristobal; Blanqué, Servane; Ibarz, D; Bertomeu Balaguero, Joan; Alcubilla Gonzalez, Ramon
    Materials science and engineering B. Solid state materials for advanced tech
    Date of publication: 2009-03
    Journal article

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  • Optoelectronic properties of CuPc thin films deposited at different substrate temperatures

     Pirriera, Della M; Puigdollers Gonzalez, Joaquin; Voz Sanchez, Cristobal; Stella, M; Bertomeu Balaguero, Joan; Alcubilla Gonzalez, Ramon
    Journal of physics D. Applied physics
    Date of publication: 2009-07
    Journal article

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  • N-type PTCDI¿C13H27 thin-film transistors deposited at different substrate temperature

     Puigdollers Gonzalez, Joaquin; Pirriera, Della M; Marsal Vinade, Albert; Orpella Garcia, Alberto; Cheylan, Stephanie; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    Thin solid films
    Date of publication: 2009-10
    Journal article

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  • 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)
    Date of publication: 2009-02
    Journal article

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  • 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
    Presentation's date: 2009-02-12
    Presentation of work at congresses

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  • SMART LIGHT COLLECTING SYSTEM FOR THE EFFICIENCY ENHANCEMENT OF SOLAR CELLS

     Martin Garcia, Isidro; Alcubilla Gonzalez, Ramon; Voz Sanchez, Cristobal; Puigdollers Gonzalez, Joaquin
    Participation in a competitive project

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  • Access to the full text
    Optimization of laser processes in n+Emitter formation for c-Si solar cells  Open access

     Orpella Garcia, Alberto; Martin Garcia, Isidro; Blanqué, Servane; Voz Sanchez, Cristobal; Sánchez Aniorte, M. Isabel; Colina Brito, Monica Alejandra; Molpeceres Alvarez, Carlos; Alcubilla Gonzalez, Ramon
    European Photovoltaic Solar Energy Conference and Exhibition
    Presentation of work at congresses

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    Punctual phosphorus diffused emitters were achieved by laser patterning phosphorus doped a-SiCx:H films deposited by PECVD as a doping source. Two different lasers at wavelengths of 1064 nm and 532 nm were used. Phosphorus diffusion was confirmed by Secondary Ion Mass Spectroscopy. We explored the effect of pulse energy and number of pulses per diffused point. The results show that a fine tune of the energy pulse is critical while the number of pulses has minor effects. Scanning Electron Microscopy (SEM) pictures and optical profilometry showed a laser affected area where the c-Si is melted, ejected and solidified quickly again. Typically, the diameter of the affected area for 1064 nm laser is between two and four times greater than for 532 nm laser. Optimum parameters for both lasers were determined to obtain best J-V curves nearly to ideal diode behavior. Comparing best J-V results, lower emitter saturation current density (Jo) and contact resistance are obtained with 532 nm laser. The improvement in Jo can be related mainly to the smaller affected areas observed by SEM while lower contact resistance can be attributed to that 532 nm laser has a more superficial action resulting in higher phosphorus concentration at the surface. The expected open voltage circuit for finished solar cells using these emitters is in the range of 640 mV for 532 nm laser and 620 mV for 1064 nm one.

  • Optical Stability of Small-Molecule Thin-Films Determined by Photothermal Deflection Spectroscopy

     Pirriera, Monica Della; Puigdollers Gonzalez, Joaquin; Cristoval, Voz; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon
    International Materials Research Congress
    Presentation of work at congresses

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  • N-type emitters passivation through antireflective phosphorus doped a-SiCxNy:H(n) stacks

     Orpella Garcia, Alberto; Blanqué, Servane; Roiati, V.; Martin Garcia, Isidro; Voz Sanchez, Cristobal; Puigdollers Gonzalez, Joaquin; Alcubilla Gonzalez, Ramon
    Spanish Conference on Electron Devices
    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
    Presentation of work at congresses

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  • Optimization of KOH etching process to obtain textured substrates suitable for heterojunction solar cells fabricated by HWCVD

     Munoz, D; Carreras Seguí, Paz; Escarré, Jordi; Ibarz, D; Nicolas, Martin De S; Voz Sanchez, Cristobal; Asensi, Jm; Bertomeu Balaguero, Joan
    Thin solid films
    Date of publication: 2009-04
    Journal article

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  • Progress in a-Si:H/c-Si heterojunction emitters obtained by Hot-Wire CVD at 200 °C

     Muñoz, D; Voz Sanchez, Cristobal; Martin Garcia, Isidro; Orpella Garcia, Alberto; Puigdollers Gonzalez, Joaquin; Alcubilla Gonzalez, Ramon; Villar, F; Bertomeu Balaguero, Joan; Andreu, Jordi; Damon-Lacoste, J; Cabarrocas, Roca I P
    Thin solid films
    Date of publication: 2008-01
    Journal article

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  • Increased conductivity of a hole transport layer due to oxidation by a molecular nanomagnet - art. no. 096110

     Cheylan, Stephanie; Puigdollers Gonzalez, Joaquin; Bolink, H J; Coronado, E; Voz Sanchez, Cristobal; Alcubilla Gonzalez, Ramon; Badenes, G
    Journal of applied physics
    Date of publication: 2008-05
    Journal article

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  • Very low surface recombination velocity of crystalline silicon passivated by phosphorus-doped a-SiCxNy:H(n) alloys

     Ferre, R; Orpella Garcia, Alberto; Munoz, D; Martin Garcia, Isidro; Recart, F; Voz Sanchez, Cristobal; Puigdollers Gonzalez, Joaquin; Cabarrocas, Roca I P; Alcubilla Gonzalez, Ramon
    Progress in photovoltaics
    Date of publication: 2008-03
    Journal article

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  • Low temperature back-surface-field contacts deposited by hot-wire CVD for heterojunction solar cells

     Munoz, D; Voz Sanchez, Cristobal; Martin Garcia, Isidro; Orpella Garcia, Alberto; Alcubilla Gonzalez, Ramon; Villar, F; Bertomeu Balaguero, Joan; Andreu, Jordi; Roca-I-Cabarrocas, P
    Thin solid films
    Date of publication: 2008-08
    Journal article

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  • Defect states in pentacene thin films prepared by thermal evaporation and Langmuir-Blodgett technique

     Nadazdy, V; Durny, R; Puigdollers Gonzalez, Joaquin; Voz Sanchez, Cristobal; Cheylan, Stephanie; Weis, M
    Journal of non-crystalline solids
    Date of publication: 2008-05
    Journal article

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  • Laser fired contacts on amorphous silicon deposited by hot-wire cvd on crystalline silicon

     Blanque, S; Voz Sanchez, Cristobal; Muñoz, D; Martin Garcia, Isidro; Orpella Garcia, Alberto; Puigdollers Gonzalez, Joaquin; Alcubilla Gonzalez, Ramon
    23rd Europeran Photovoltaic Solar Energy Conference
    Presentation of work at congresses

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  • Silicon Heterojunction Solar Cells fabricated by Hot -Wire CVD

     MUÑOZ CERVANTES, DELFINA
    Defense's date: 2008-07-21
    Department of Electronic Engineering, Universitat Politècnica de Catalunya
    Theses

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

     Voz Sanchez, Cristobal; Calderer Cardona, Josep; Bermejo Broto, Alexandra; Ortega Villasclaras, Pablo Rafael
    Participation in a competitive project

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