Enhanced Performance of Gallium‐Based Wide Bandgap Oxide Semiconductor Heterojunction Photodetector for Solar‐Blind Optical Communication via Oxygen Vacancy Electrical Activity Modulation

Abstract

Abstract Gallium oxide ( β ‐Ga 2 O 3 ) is a prominent representative of the new generation of wide‐bandgap semiconductors, boasting a bandgap of ≈4.9 eV. However, the growth process of β ‐Ga 2 O 3 materials introduces unavoidable oxygen vacancies (Vo), leading to persistent photoconductivity (PPC), a phenomenon that severely hinders device performance. In this study, an innovative approach is successfully developed by introducing high p‐orbital energy nitrogen (N). This leads to the formation of a hybridized state with O 2p orbitals in β ‐Ga 2 O 3 , resulting in the creation of GaON and suppressing the electrical activity of Vo. Through meticulous experimentation and advanced computational methods, a comprehensive and insightful explanation of the regulation and mechanism underlying this passivation process is offered. Moreover, pn ‐junction solar‐blind photodetectors are engineered using hybridized GaON thin films with p ‐type CuPc. These photodetectors demonstrate exceptional characteristics, including ultra‐low dark current (10 −14 A), high photo‐to‐dark current ratio (10 6 ), and rapid decay speed (0.008 s) even at zero bias. Based on these advancements, a solar‐blind ultraviolet communication system is designed, featuring straightforward and reliable encoding, easy implementation, and robust anti‐interference capabilities.