New material lattice matched to InP for 0.45-0.6 eV photovoltaic applications

Recently, short period superlattice composed of alternate ultra-thin layers of Ga_1-xAs_xN (biaxially tensile) and InAs (biaxially compressive) strained to InP [001] is shown to achieve photon absorption/emission at energies in 0.4-0.6 eV range, with potential structure for mid-IR applications. Theoretical investigation of effects of the incorporation of such a novel superlattice structure in I (intrinsic) region of p-I-n device is done under a depletion approximation. Photocurrent is calculated by solving the semiconductor transport equations under the negligible electric field approximation. It is shown that the wavelength response of the device is increased significantly towards the mid-infrared regime with the incorporation of the superlattice in active region with positive impact on the overall efficiency.