Self-powered MSM deep-ultraviolet β-Ga2O3 photodetector realized by an asymmetrical pair of Schottky contacts

Self-powered photodetectors working in solar-blind region (below 280 nm) have attracted growing attention due to their wide applicability.Monoclinic Ga 2 O 3 (β-Ga 2 O 3 ) with excellent merits and a wide bandgap (4.9 eV) is regarded as a good candidate for solar-blind photodetector application.Self-powered photodetectors generally based on homo/heterojunction suffer from a complex fabrication process and slow photoresponse because of the interface defects and traps.Herein, we demonstrated a fabrication and characterization of a self-powered metal-semiconductor-metal (MSM) deep-ultraviolet (DUV) photodetector based on single crystal β-Ga 2 O 3 .The self-powered property was realized through a simple one-step deposition of an asymmetrical pair of Schottky interdigital contacts.The photocurrent and responsivity increase with the degenerating symmetrical contact.For the device with the most asymmetric interdigital contacts operated at 0 V bias, the maximum photocurrent reaches 2.7 nA.The responsivity R λ , external quantum efficiency EQE, detectivity D*, and linear dynamic range LDR are 1.28 mA/W, 0.63, 1.77 × 10 11 Jones, and 23.5 dB, respectively.The device exhibits excellent repeatability and stability at the same time.Besides, the device presents a fast response speed with a rise time of 0.03 s and a decay time of 0.08 s.All these results indicate a promising and simple method to fabricate a zeropowered DUV photodetector.