Self-Powered Solar-Blind UV Detectors Based on O-Terminated Vertical Diamond Schottky Diode with Low Dark Current, High Detectivity, and High Signal-to-Noise Ratio

Self-powered solar-blind UV detectors were fabricated using high-quality Ru/diamond Schottky diodes. Photocurrents of 1 nA and 1.3 nA were obtained for detector Semi and Mesh under the condition of zero bias and 220 nm UV light irradiation, while the dark currents of these two detectors were 0.53 pA and 0.007 pA at 0 V, respectively. Photosensitive areas of detector Semi and Mesh were 1 mm²and 0.74 mm², respectively. Rectification ratios as high as 1.5 × 10⁷and 5.7 × 10⁸at ±5 V for Semi and Mesh were obtained, showing good rectifying characteristics for the vertical Schottky diodes. Responsivities at 0 V of Semi and Mesh were 10.3 mA/W and 16.2 mA/W, respectively. High detectivities of 3.8 × 10¹²Jones and 5.2 × 10¹³Jones for detector Semi and Mesh indicate excellent self-powered detection performance. To make a comprehensive comparison of the performance of diamond solar-blind UV detectors, a log(I_ph) versus log(I_dark) graph was proposed, and the detector in this work showed an ultrahigh SNR of 2 × 10⁵. A high linear dynamic range of 105.9 dB was achieved for the self-powered detector Mesh.