Gate‐Controlled Graphene–Silicon Schottky Junction Photodetector

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2018-07, Vol.14 (28), p.e1801182-n/a
• Main Authors: Chang, Kyoung Eun, Yoo, Tae Jin, Kim, Cihyun, Kim, Yun Ji, Lee, Sang Kyung, Kim, So‐Young, Heo, Sunwoo, Kwon, Min Gyu, Lee, Byoung Hun
• Format: Article
• Language: English
• Subjects: Carrier transport; Dark current; Graphene; graphene–silicon heterostructure photodetectors; graphene–silicon hybrid photodetectors; heterostructures; hybridstructures; Nanotechnology; photodetectors; Photometers; Schottky contacts; Silicon
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201801182

Various photodetectors showing extremely high photoresponsivity have been frequently reported, but many of these photodetectors could not avoid the simultaneous amplification of dark current. A gate‐controlled graphene–silicon Schottky junction photodetector that exhibits a high on/off photoswitching ratio (≈104), a very high photoresponsivity (≈70 A W−1), and a low dark current in the order of µA cm−2 in a wide wavelength range (395–850 nm) is demonstrated. The photoresponsivity is ≈100 times higher than that of existing commercial photodetectors, and 7000 times higher than that of graphene‐field‐effect transistor‐based photodetectors, while the dark current is similar to or lower than that of commercial photodetectors. This result can be explained by a unique gain mechanism originating from the difference in carrier transport characteristics of silicon and graphene. A gate‐controlled graphene–silicon Schottky junction photodetector that exhibits a high photoresponsivity and a low dark current with a high on/off photo switching ratio is demonstrated. This result is explained by a unique gain mechanism originating from the gate‐controlled graphene–silicon interface.