High interface recombination velocity caused by spatially indirect quantum well transition in Al0.55In0.45As/InP heteroface solar cells

The effect of a strained Al0.55In0.45As window layer on p/n InP solar cell performance was studied. In comparison to homojunction InP solar cells, decreased quantum efficiency in the short wavelength region of the spectrum was observed in cells having the window layer. Photoluminescence measurements of the heterojunction and light emission measurements of the solar cell under forward bias revealed an intense radiative transition, which is related to the enhanced recombination of the carriers that are photogenerated in the emitter layer. This recombination occurs between the energy levels of the triangular quantum wells formed at the type II Al0.55In0.45As/InP heterojunction, and prevents effective carrier collection in the solar cell.