Self-Powered Wavelength-Selective Ultraviolet Bipolar Photodetector Based on Al/p-GaN/In:Ga 2 O 3 /SnO 2 Structure for Secure Optical Communication

Jones, for 254 and 365 nm illumination, respectively. Leveraging the unique physical properties of the photodetector, a secure optical communication (SOC) system is demonstrated. This system utilizes the positive and negative photocurrents, generated by distinct UV wavelengths, as binary signals ("1" and "0") to encrypt information, while decryption is performed at the receiving end using a preset key file. The experimental results demonstrate that the system successfully achieved the encrypted transmission and accurate decryption of the string "CUST" at zero bias. This work not only presents a new strategy for developing high-performance, multifunctional bipolar UV photodetectors but also offers an innovative and viable technological pathway for fabricating next-generation, high-security, and low-power optical communication systems.