Core-shell ferroelectric nanowire arrays for photovoltaic applications

Abstract

Bismuth ferrite (BFO), as an inorganic perovskite metal oxide without Pb, is a potential photovoltaic material for solar cells. However, the low optical absorption and carrier transport ability of BFO limits the improvement of its photoelectric conversion efficiency. In this work, a transmission layer/ferroelectric layer/transmission layer shell-core nanowire array is constructed to verify its application in photovoltaics. With its large specific surface area, this structure can enhance light absorption. In particular, TiO2 nanowire arrays are used as an electron transport layer, BFO as a light absorption layer, and WO3 as a hole transport layer. With an increase in external bias, the device's photovoltaic performance first increases before decreasing. TiO2/BFO/WO3 device produced an open-circuit voltage (Voc) and short-circuit current density (Jsc) of 1.32 V and 1.14 mA/cm2, respectively, when the scanning bias is 1.75 V. The photoelectric conversion efficiency (PCE) reached 0.93 %, which is significantly higher than that of previous reports on BFO-based photovoltaic devices. As a result of this work, core-shell nanowire arrays have potential applications in the photovoltaics field.