Optoelectronic and Ionic Effects on Transport in van der Waals Metal Selenophosphate AgBiP2Se6

Metal thio(seleno)phosphates are a large family of homologous layered compounds hosting a rich variety of physical properties and potential applications. Besides the extensively explored optoelectron-ics, ferroelectric, and magnetic orders, mobile ions recently arise as an additional degree of freedom for creating emergent functionalities. Herein, we report the active manipulation of the electronic trans-port characteristics in a quaternary selenophosphate, AgBiP2Se6. By electrically driven accumulation or removal of mobile Ag+ ions at the metal-semiconductor interface, the Schottky barrier can be effectively modulated to produce switchable diodelike behavior with tunable rectification ratios as explicitly revealed by correlated elemental, spatial photocurrent, and surface potential microscopies. Furthermore, the supe-rior photoelectric response of AgBiP2Se6 is demonstrated and can be incorporated to turn the induced rectifying transport off and on. The combined optoelectronic and ionotronic activities greatly expand the versatility of AgBiP2Se6 and related selenophosphates in next-generation electronic applications.