Filterless Visible‐Range Color Sensing and Wavelength‐Selective Photodetection Based on Barium/Nickel Codoped Bandgap‐Engineered Potassium Sodium Niobate Ferroelectric Ceramics

Ultrahigh Bulk Photovoltaic Effect Responsivity in Thin Films: Unexpected Behavior in a Classic Ferroelectric Material

“…Furthermore, our results suggest that a film with a polarization gradient through the entire film thickness may exhibit a high PCE. In such a film, deviation from periodicity is obtained throughout the film rather than only in the vicinity of the FEelectrode interface, so that the ultrahigh-BPE hot-carrier scattering effect will enable photocurrent generation even in the region far from the film-electrode interface, allowing the use of thick films, which can achieve higher-than-bandgap V OC simply by increasing the film thickness due to the linear dependence of V OC on d. Aditionally, even with a V OC under the E g , PV devices based on BPE can be used for wavelength-sensitive photodetection [44] and for low-intensity light harvesting, due to the lack of dependence of PCE on light intensity. In theoretical research, further efforts are necessary to develop a microscopic, first-principles-based description of the strong BPE effect in thin films that incorporates the effect of the interface and enables first-principles calculations to provide guidance for further BPE device design efforts.…”