On the demand of single‐photon entangled light sources and high‐sensitivity probes in the fields of quantum information processing, weak magnetic field detection and biosensing, the nitrogen vacancy (NV) color center is very attractive and has been deeply and intensively studied, due to its convenience of spin initialization, operation, and optical readout combined with long coherence time in the ambient environment. Although the application prospect is promising, there are still some problems to be solved before fully exerting its characteristic performance, including enhancement of emission of NV centers in certain charge state (NV− or NV0), obtaining indistinguishable photons, and improving of collecting efficiency for the photons. Herein, the research progress in these issues is reviewed and commented on to help researchers grasp the current trends. In addition, the development of emerging color centers, such as germanium vacancy defects, and rare‐earth dopants, with great potential for various applications, are also briefly surveyed.

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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 mm 2 and 0.74 mm 2 , respectively. Rectification ratios as high as 1.5 × 10 7 and 5.7 × 10 8 at ±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 × 10 12 Jones and 5.2 × 10 13 Jones 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 × 10 5 . A high linear dynamic range of 105.9 dB was achieved for the self-powered detector Mesh.