Catalyst-Free Vapor-Solid Deposition Growth of β-Ga2O3 Nanowires for DUV Photodetector and Image Sensor Application

Photodetection in the solar-blind deep-ultraviolet (DUV) regime (200-280 nm) has received significant attention for its many critical applications in military and civil areas. In this study, a vapor-solid synthesis technique for catalyst-free growth of single-crystalline beta-Ga2O3 nanowires is developed. A photodetector made of the nanowires is highly sensitive to 265 nm DUV illumination with excellent photoresponse performance. The performance parameters including I-light/I-dark ratio, responsivity, specific detectivity and response speed can attain approximate to 10(3), approximate to 233 A W-1, approximate to 8.16 x 10(12) Jones, and 0.48/0.04 s, respectively. Additionally, the detector has an abrupt response cutoff wavelength at approximate to 290 nm with a reasonable DUV/visible (250-405 nm) rejection ratio exceeding 10(2). It is also found that the device can operate properly at a large applied bias of 200 V with the responsivity being enhanced to as high as approximate to 1680 A W-1. Moreover, such a nanowires-based photodetector can function as a DUV light image sensor with a reasonable spatial resolution. Holding the above advantages, the present DUV photodetector based on catalyst-free grown beta-Ga2O3 nanowires possesses huge possibility for application in future DUV optoelectronics.