High rectification and photovoltaic effect in oxide nano-junctions

Abstract

Polar oxide-based heterostructures composed of ferroelectric PbZr 0.2Ti 0.8O 3 and hole-doped La 0.8Sr 0.2MnO 3 ultrathin epitaxial films were fabricated on Nb: SrTiO 3 substrates to check the viability of all oxide-based photovoltaic (PV) nano-junctions. We observed clear diode-like behavior, yielding a rectification ratio up to ∼1000. This large enhancement could be attributed to the presence of an ultrathin ferroelectric layer (<10 nm) that greatly contributed to the improved PV performance by promoting carrier separation, as compared with oxide junctions without the ferroelectric layer. Therefore, our results provide useful information for developing highly efficient ferroelectric oxide-based PV devices. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.