Heterojunction solar cells on cuprous oxide

Abstract Heterojunction solar cells were made on Cu2O by sputtering In2O3, SnO2, CdO and mixtures of CdO and SnO2 and by thermal evaporation of ZnSe. Photovoltaic effects were observed in most cases. High series resistances were an indication of chemical reactions at the interface. Auger surface analysis showed evidence of copper metal at the interface, arising from chemical reactions. For a CdO/Cu2O junction formed at room temperature, no copper metal was found at the interface. The CdO/Cu2O cells showed V oc = 0.4 V and I sc = 2 mA cm −2 . The properties appear to be dominated by a multiple-step tunneling at the junction, presumably due to dislocations and impurities in the Cu2O samples as prepared.