This report describes the electrical and photovoltaic properties in heterojunction devices consisting of a cuprous oxide (Cu2O) sheet and a transparent conducting oxide (TCO) thin film, such as In2O3, ZnO, In2O3:Sn (ITO), ZnO:Al (AZO) or AZO-ITO (AZITO) multicomponent oxide, prepared by pulsed laser deposition (PLD). Undoped In2O3-Cu2O heterojunctions prepared by PLD exhibited ohmic current voltage (I-V) characteristics. The ZnO-Cu2O and AZO-Cu2O devices exhibited better rectifying I-V characteristics and photovoltaic properties than the ITO-Cu2O devices. It was found that the obtainable I-V characteristics and photovoltaic properties were considerably affected by the TCO film deposition conditions. An open-circuit voltage (V-OC) of 0.4 V, a short-circuit current density (J(SC)) of 7.1 mA/cm(2), a fill factor (F.F.) of 0.4 and an energy conversion efficiency (eta) of 1.2% were obtained in an AZO-Cu2O device under AM2 solar illumination. The V-OC, J(SC), F.F. and eta obtained in AZITO-Cu2O heterojunctions increased as the Zn/(Zn+In) atomic ratio was increased. (C) 2004 Elsevier B.V. All rights reserved.