OPTICAL-PROPERTIES OF A-SIGE-H SOLAR-CELLS ON TEXTURED SUBSTRATES

The optical numerical simulator for multi-layer structures with textur ed interfaces, GENPRO2, was improved and applied to determine the scat tering parameters of textured interfaces of a-SiGe:H solar cells. A se nsitivity study was carried out in which the relative effects of the v arious scattering parameters of the interfaces on the quantum efficien cy (QE) of the solar cells were investigated. The optical properties o f the separate layers were determined and extrapolated to energies at which they could not be measured accurately. A series of four a-SiGe:H solar cells with various thicknesses of the intrinsic layer was grown and their QE properties were measured. The contribution of the scatte ring of the various interfaces was determined by matching the measured and the simulated QE properties. The haze values of the transparent c onductive oxide/p-doped layer (TCO/p) interface found by our simulatio ns agree well with reports in the literature. In contrast to other mod el results, we show that besides the scattering at the TCO/p- and n-do ped layer/Ag interface, the scattering at the p/insulator and the insu lator/n interface also has to be taken into account in calculating the QE characteristics. (C) 1998 Elsevier Science B.V. All rights reserve d.