High performance diamond-based solar-blind photodetectors enabled by Schottky barrier modulation

• Published in: Carbon (New York) Vol. 200; pp. 510 - 516
• Main Authors: Lin, Chao-Nan, Zhang, Zhen-Feng, Lu, Ying-Jie, Yang, Xun, Zhang, Yuan, Li, Xing, Zang, Jin-Hao, Pang, Xin-Chang, Dong, Lin, Shan, Chong-Xin
• Format: Journal Article
• Language: English
• Published: 05.11.2022
• Subjects: carbon; electric current; hydrogen; lighting; thermal conductivity
• ISSN: 0008-6223
• DOI: 10.1016/j.carbon.2022.09.001

Diamond, which possesses an ultra-wide bandgap, high thermal conductivity, and super thermal and chemical stability, is a promising material for deep-ultraviolet optoelectronics. However, it is still difficult for diamond photodetectors to meet the requirements of practical applications due to their relatively low responsivity. Here, we demonstrate a high-performance diamond photodetector realized via Schottky barrier modulation. Defect states and hydrogen terminals are introduced onto the surface of the diamond by hydrogen plasma treatment. Under illumination, photon-generated electrons are trapped by the defect states at the surface of the diamond, which lowers dramatically the Schottky barrier height, leading to high photocurrent of the photodetector. As a result, our device exhibits a responsivity of 524.9 A/W, a gain of 2958, and a detectivity of 3.42 × 10¹⁵ cm Hz¹/² W⁻¹, all of which are among the highest values ever reported for diamond-based photodetectors. Thus, our results suggest a novel strategy for design and fabrication of high-performance diamond photodetectors.