Effect of a buffer layer on the photovoltaic properties of AZO/Cu 2 O solar cells

Abstract

The effect of a buffer layer and/or interface region on the photovoltaic properties of Al-doped ZnO (AZO)/Cu2O heterojunction solar cells was investigated. The I-V characteristics and photovoltaic properties in AZO/ZnO-In2O3/Cu2O devices were considerably improved by increasing the Zn content (Zn/(In + Zn at. ratio)) of the ZnO-In2O3 thin-film buffer layer. In addn., the photovoltaic properties of AZO/Zn1-xMgxO/Cu2O devices degraded significantly as the compn. (x) was increased above ∼0.1 because of the increase in resistivity of the buffer layer. Although the spectral response of photocurrent obsd. in AZO/Zn1-xMgxO/Cu2O devices was considerably affected by altering the value of X, the photo-generated hole in the buffer layer of these devices was not successfully injected into the Cu2O. AZO/Cu2O heterojunctions fabricated using Cu2O sheets with a sulfurized surface exhibited ohmic I-V characteristics. [on SciFinder(R)]