A programmable logic gate constructed with Ga₂O₃/CdS self-powered photodetector based on the pyro-phototronic effect: A new avenue for achieving secure encrypted optical communication

The integration of advanced encryption technologies is essential for meeting the rigorous standards of data protection in contemporary data security. Developing broadband, high-sensitivity photodetectors is crucial for enhancing the application of photodetectors in secure optical communications. A self-powered photodetector based on Ga₂O₃/CdS was developed, which leverages the pyro-phototronic effect to achieve a broadband response ranging from 200 nm to 1100 nm, surpassing the limitations imposed by the material's intrinsic bandgap. Compared to scenarios where only the photovoltaic effect is relied upon, this self-powered PD exhibits significantly improved responsivity (R) and specific detectivity (D*) across all wavelengths of illumination, with a particular performance enhancement of 536 % under 460 nm light. Furthermore, programmable logic gates are constructed leveraging the photoresponse characteristics based on the pyro-phototronic effect, and three logic functions—“AND”, “OR”, and “XOR”—are successfully implemented within the same device. And the encryption and decoding of a piece of information are successfully achieved. This study not only advances the theoretical understanding and application scope of the pyro-phototronic effect but also provides a novel strategy for efficient and secure encrypted optical communication.