Catalyst‐Free Vapor–Solid Deposition Growth of β‐Ga 2 O 3 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 β‐Ga 2 O 3 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 ≈10 3 , ≈233 A W −1 , ≈8.16 × 10 12 Jones, and 0.48/0.04 s, respectively. Additionally, the detector has an abrupt response cutoff wavelength at ≈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 ≈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 β‐Ga 2 O 3 nanowires possesses huge possibility for application in future DUV optoelectronics.