Characteristics of MOS solar cells built on (n-type) InP substrates

Abstract

An examination is made of the electrical and photovoltaic characteristics of Au- (n-type) InP Schottky-barrier solar cells with and without a thin anodic oxide layer at the interface. Cells built on anodized surface (MOS type) exhibit a reduction of dark current by three orders of magnitude and an increase in the barrier height (≃ 0.80 eV) by 0.30 eV, over conventional Schottky-barrier devices. Current transport in both type of cells is limited by thermionic emission of carriers and an increase in n factor from 1.02 to 1.16 is observed for MOS cells. Under illumination, MOS cells show an increase of open-circuit voltage to 0.46 V without any reduction in the short-circuit current which is obtained as 17.20 mA/cm2. The efficiency has been found to go up from 3.45 to 6 percent for MOS cells which show an excellent spectral response, almost flat over a large portion of the visible spectrum.