Impact of electrodes on the extraction of shift current from a ferroelectric semiconductor SbSI

摘要： Noncentrosymmetric bulk crystals generate photocurrent without any bias voltage. One of the dominant mechanisms, shift current, comes from the quantum interference of electron wave functions being distinct from the classical current caused by electrons’ drift or diffusion. The dissipation-less nature of shift current, however, has not been fully veri?ed, presumably due to the premature understanding of the role of electrodes. Here, we show that the photocurrent dramatically enhanced by choosing electrodes with large work functions for a p-type ferroelectric semiconductor SbSI. An optimized device shows a nearly constant zero-bias photocurrent despite the signi?cant dependence of photocarrier mobility on temperature, which could be a clear hallmark for the dissipation-less nature of shift current. Distinct from conventional photovoltaic devices, the shift current generator operates as a majority carrier device. The present study provides fundamental design principles for energy-harvesting and photo-detecting devices with novel architectures optimal for the shift current photovoltaic effect.