Influence of the Interfacial Layer on Electrooptical Properties of Heterojunction Solar Cells. Final Report

摘要

We have investigated the influence on the photovoltaic characteristics of the interfacial (I) layers of silicon oxide which spontaneously form in heterojunction solar cells with Si as active substrate material and SnO sub 2 , In sub 2 O sub 3 and indium-tin oxide (ITO) as windows. We have verified the reported dependence of the growth rate of the I layer on the Si conductivity type but we disproved the hypothesis that the increased degradation rate of cells with n-Si substrates compared to those with p-Si substrates results from field-enhanced diffusion of O sub 2- ions. We have preliminary results which suggest that the conversion efficiency is largely controlled by the sign and quantity of interfacial charge. For large values of open circuit voltage, as required in cells of high efficiency, this charge is positive for cells using p-Si substrate and negative for n-Si based devices. The charge is apparently a result of the fabrication method. (ERA citation 09:032846)