Polycrystalline n ‐ZnO/ p ‐Cu 2 O heterojunctions grown by RF‐magnetron sputtering

Polycrystalline n-ZnO/p-Cu2O heterojunctions were fabricated by reactive sputtering for photovoltaic applications. Although electrical rectification was not reproducibly obtained in the as-grown samples, rectification was observed in the samples fabricated with cyanide treated Cu2O. We have previously shown that cyanide treatment has an effective role in passivation of defects in Cu2O, in analogy to hydrogen passivation. It is, therefore, believed that the observed improvement in the electrical rectification of the ZnO/Cu2O heterojunctions is attributable to the defect passivation near the hetero-interface. The effectiveness of the cyanide treatment and the importance of defect passivation in ZnO/Cu2O heterojunctions are presented. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)