Optically Controlled Abnormal Photovoltaic Current Modulation with Temperature in BiFeO3

Ferroelectric materials hold great promise toward next generation of optoelectronic devices because of their unique characteristics such as above-bandgap photovoltage and polarization-dependent photocurrent. But the relative low photocurrent value limits their potential applications in real devices. In order to improve the photovoltaic performance and detailed and systematic investigations about the role of temperature gradient on the photocurrent in indium tin oxide (ITO)/BiFeO3 (BFO)/ITO device under various temperature gradients across both sides are carried out. The observed results reveal an enhancement in photocurrent under applying different temperature gradients, which is mainly associated with light intensity. The applied temperature gradients induce interesting mechanisms under weak and strong lights. Due to the temperature gradient controlled photocurrent, the photosensing performance of ITO/BFO/ITO photodetector device with respect to 365 nm light can be strongly modulated. This presented strategy offers a feasible route for enhancing the photovoltaic performances of the BFO material based device, which offers the capability to push forward the practical applications of ferroelectric photovoltaic devices.