Reconfigurable and Giant Bulk Ionicphotovoltaic Effect in 2D Quaternary Metal Thio(Seleno)Phosphates Crystals

Abstract Lamed by the Shockley–Queisser limit, complex device architectures and material selection, traditional photovoltaic (PV) technologies based on heterojunctions are difficult to implement reconfigurable PV generation with high power efficiency. Here, the universal bulk ionicphotovoltaic (BIPV) effect in 2D quaternary metal thio(seleno)phosphates (QMTPs) crystals is reported, and demonstrates the giant photocurrent generation with excellent reconfigurability. The programmable ion migration driven by an electric field not only leads to the in‐plane electric potential gradient, but also contributes to the reversible modulation of crystal inversion asymmetry. The formation of reconfigurable in‐plane homojunction in 2D CuBiP 2 Se 6 channel results into the pronounced conductance rectification with a high ratio exceeding 10 3 , contributing to an extremely large short‐circuit PV current density of 1.6 A cm −2 under 532 nm illumination, among the highest values of state‐of‐the‐art 2D PV devices. More importantly, the electric potential gradient and degree of centrosymmetric of 2D QMTPs channel can be precisely controlled by the direction and magnitude of programming voltage pulses, which enables the linearly programmed BIPV current generation with an ideal nonlinearity factor of 0.09. The photoelectric conversion relying on the BIPV effect breaks the integration bottleneck of reconfigurability and power efficiency, providing a transformative strategy for developing next‐generation PV devices.