Interface‐Engineering Induced Swift and Controllable Solar‐Blind Photoresponse in Ga₂O₃/SiC Heterojunction Based on Unconventional Rectification Characteristics

Abstract

Ga₂O₃ photodetectors with demonstrated high sensitivity provide a potential subversive scheme for solar‐blind photodetection. However, the planar structure and the relatively slow response speed of the device have restricted the integration and application of Ga₂O₃ photodetectors. Herein, a narrow SiO₂ barrier layer is introduced on the commercial SiC substrate, and a vertical photodetector is realized based on β‐Ga₂O₃/SiO₂/SiC heterostructure with controllable tunneling effect by tailoring the band structure at the interface. The developed device exhibits unconventional rectification characteristics and photoresponse performance in different biasing modes owing to the controllable tunneling effect at the interface. In particular, the photodetector achieves a high responsivity (186.8 A W⁻¹) under solar‐blind illumination at reverse bias, while exhibiting obvious advantages in dark current (3 pA), photo‐to‐dark current ratio (8.8 × 10⁶), linear dynamic range (138.8 dB), and specific detectivity (1.4 × 10¹⁵ Jones) at forward bias. The photodetector also demonstrates excellent photoresponse stability after 6 months in air without encapsulation. In addition, an alternating biasing strategy, inspired by its bidirectional operability, is proposed to suppress the persistent photoconductivity effect and increase the decay speed by 1.23 × 10⁵ times. This work provides a referable strategy for the further development of high‐performance Ga₂O₃‐based photoelectronics.