In this work we present the manufacturing processes and results obtained from the characterization of heterojunction with intrinsic thin layer solar cells that include a heavily Ti ion implanted Si absorbing layer. The cells exhibit external circuit photocurrent at photon energies well below the Si bandgap. We discuss the origin of this below-bandgap photocurrent and the modifications in the hydrogenated amorphous intrinsic Si layer thickness to increase the open-circuit voltage.
Silvestre, S. [et al.]. Sub-Bandgap external quantum efficiency in Ti implanted Si heterojunction with intrinsic thin layer cells. "Japanese journal of applied physics", Novembre 2013, vol. 52, p. 122302-1-122302-5.