Spontaneously Oxidized CuxO/β-Ga2O3 p-n Junction for Self-Powered Deep-Ultraviolet Photodetection

In this work, we demonstrate the fabrication of CuxO/Ga2O3 heterojunction through the spontaneous oxidation of Cu film into CuxO layer during electron beam evaporation. The heterojunction device presents a ultraviolet (UV)/visible rejection ratio (R-265/R-430) at zero bias of 435, enabling the self-powered deep-UV (DUV) photodetection. Upon 265-nm illumination (light intensity: 21.7 mu W.cm(-2)), the responsivity (R) and specific detectivity (D*) reach 0.97 mA.W-1 and 6.28 x 10(10) Jones, respectively. A fast response speed of 5.34/3.64 ms (tau(r)/tau(f)) has also been observed, which may ascribe to the fully depleted thin CuxO layer and suggest the ability to detect rapidly switched optical signal. This work sheds light on the facile fabrication of beta-Ga2O3 -based self-powered DUV photodetectors.

Automated summary

In this work, a CuxO/Ga2O3 heterojunction was fabricated through the spontaneous oxidation of Cu film during electron beam evaporation. The heterojunction device exhibited a UV/visible rejection ratio of 435 at zero bias, enabling self-powered deep-UV photodetection. With 265-nm illumination, the responsivity and specific detectivity reached 0.97 mA.W-1 and 6.28 x 10(10) Jones, respectively. The device also showed a fast response speed, which can be attributed to the fully depleted thin CuxO layer, suggesting its ability to detect rapidly switched optical signals. This work sheds light on the facile fabrication of self-powered DUV photodetectors based on β-Ga2O3.