The dependence of a-Si:H/c-Si solar cell generator and spectral response characteristics on heterojunction band discontinuities

Abstract Solar Cells consisting of an amorphous silicon emitter on a crystalline silicon base were prepared by PECVD. Measured generator and bias-dependent spectral response characteristics of these devices were interpreted by aid of numerical simulations. By comparison of simulation results and measured data the distribution of the heterojunction band-discontinuities of valence and conduction bands can be estimated. We obtain Δ E C ≈ 0.25 Δ E G and Δ E V ≈ 0.75 Δ E G respectively with slight dependence on deposition conditions. The limiting effect of ΔE V on minority carrier transport from the crystalline base into the amorphous silicon produces a switchable “blue/white” sensitivity in our devices.