Polarity‐Reconfigurable In 1.5 Mn 0.5 Se 3 Photodetectors Enabled by Asymmetric Schottky Barriers Toward Optical‐Electrical Logic Gates and Encryption Communication Application

Ensuring information security at the device level is a critical demand in the era of ubiquitous sensing and communication. In this work, we design an asymmetric two‐terminal Schottky photodetector based on Mn‐doped In 2 Se 3 . The regulation mechanism of Mn doping on electronic structure, interfacial charge distribution, and carrier transport is systematically investigated, and high‐performance optoelectronic logic operations and optical information encryption, decryption are realized. First‐principles calculations reveal that Mn doping can effectively narrow the bandgap of In 2 Se 3 from 1.0878 to 0.8986 eV and introduce donor impurity levels, significantly improving carrier concentration and optical absorption. Benefiting from the polarity‐tunable photoresponse enabled by asymmetric Schottky barriers, the device successfully implements multifunctional optoelectronic logic gates including XNOR, NAND, NOR etc. Furthermore, a complete optical information encryption and decryption system is constructed based on the XNOR logic, realizing secure encoding and accurate recovery of plaintext information. This work not only provides an effective strategy for doping modification and interface engineering of two‐dimensional semiconductors, but also offers new concepts and experimental support for high‐performance devices toward next‐generation optoelectronic computing and optical communication security.