Photoluminescence studies of a-Si:H/c-Si-heterojunction solar cells

We have performed room-temperature photoluminescence studies under AM1.5-equivalent photon flux on c-Si wafers in order to study the bulk and surface properties after the deposition of a variety of a-Si:H layers for a-Si:H/c-Si heterojunction solar cell applications. The results show a strong dependence of photoluminescence yield on the surface treatment prior to a-Si:H deposition and on the type of the p- and n-type as well as undoped amorphous silicon passivation layers. Photoluminescence emission recorded under different operating conditions of a heterojunction solar cell device shows the influence of interface states on the quasi-Fermi level splitting. Numerical simulation results confirm the observed sensitivity of the photoluminescence yield on the interface states.