Giant Polarization Sensitivity via the Anomalous Photovoltaic Effect in a Two-Dimensional Perovskite Ferroelectric

Polarization sensitivity, which shows great potentialin photoelectricdetection, is expected to be significantly improved by the ferroelectricanomalous photovoltaic (APV) effect. However, it is challenging toexplore new APV-active ferroelectrics due to severe polarization fatigueinduced by the leakage current of photoexcited carriers. For the firsttime, we report a strong APV effect in a 2D hybrid perovskite ferroelectricassembled by alloying mixed organic cations, (HA)(2)(EA)(2)Pb3Br10 (1, where HA(+) is n-hexylammonium and EA(+) isethylammonium), which has a large spontaneous polarization & SIM;3.8 & mu;C/cm(2) and high a Curie temperature & SIM;378 K.Its ferroelectricity allows a strong APV effect with an above-bandgapphotovoltage up to 7.4 V, which exceeds its bandgap (& SIM;2.7 eV).Most strikingly, based on the dependence on polarized-light angle,this strong APV effect renders the highest level of polarization sensitivitywith a giant current ratio of & SIM;25, far beyond other 2D single-phasematerials. This study sheds light on the exploration of APV-activeferroelectrics and inspires their future high-performance optoelectronicdevice applications.

Automated summary

In this study, a strong anomalous photovoltaic (APV) effect was demonstrated in a 2D hybrid perovskite ferroelectric material, achieved by alloying mixed organic cations. The material exhibited a high level of polarization sensitivity, with a giant current ratio and an above-bandgap photovoltage exceeding its bandgap. This research sheds light on the exploration of APV-active ferroelectrics and inspires their future optoelectronic device applications.