Impact of piezo-phototronic effect on ZnMgO/Se heterojunction photovoltaic devices

This paper investigates the impact of piezo-phototronic effects on the power conversion efficiency of ZnMgO/Se heterojunction photovoltaic devices. Sputter-deposited ZnMgO thin film and photo-absorbing Se were employed as the n-type window layer and p-type layer, respectively, to form a photovoltaic device on a flexible polyethylene terephthalate film. The applied strain was varied, and the changes due to the applied strain were recorded. The open-circuit voltage ( V oc ) increased from 0.59 V to 0.75 V when the applied strain was increased from − 0.41–0.40% by varying the bending angle. It has been reported that piezoelectric polarization of ZnMgO can decrease conduction band offset (CBO) between the ZnMgO and Se layers. The impacts of mechanical strain on photovoltaic performance of ZnMgO/Se heterojunction device were investigated. ZnMgO/Se photovoltaic devices fabricated on flexible PET films successfully increased open circuit voltages from 0.59 V to 0.75 V, when the applied strain was increased from − 0.41–0.40% by varying its bending angle. Sputter-deposited ZnMgO thin film was used as a piezoelectric n-type window layer instead of ZnO nanowire which has conventionally been used for piezophototronic studies. It is suggested that piezoelectronic polarization on ZnMgO can decrease conduction band offset between ZnMgO and Se layers. • Piezo-phototronic effect to sputter-deposoited ZnMgO/Se heterojunction photovoltaic devices for the first time. • Demonstration of the increased V oc of ZnMgO/Se photovoltaic devices on PET films under a static strain. • V oc increased from 0.59 V to 0.75 V with increasing strain from − 0.40–0.40%.