Gate-Controlled Graphene-Silicon Schottky Junction Photodetector

Kyoung Eun Chang; Tae Jin Yoo; Cihyun Kim; Yun Ji Kim; Sang Kyung Lee; So-Young Kim; Sunwoo Heo; Min Gyu Kwon; Byoung Hun Lee

doi:10.1002/smll.201801182

Gate-Controlled Graphene-Silicon Schottky Junction Photodetector

Small. 2018 Jul;14(28):e1801182. doi: 10.1002/smll.201801182. Epub 2018 Jun 7.

Authors

Kyoung Eun Chang¹, Tae Jin Yoo¹, Cihyun Kim¹, Yun Ji Kim¹, Sang Kyung Lee¹, So-Young Kim¹, Sunwoo Heo¹, Min Gyu Kwon¹, Byoung Hun Lee^{1

1}

Affiliation

¹ School of Materials Science and Engineering, Center for Emerging Electronic Devices and Systems, Gwangju Institute of Science and Technology, Gwangju, 500-712, Republic of Korea.

PMID: 29877040
DOI: 10.1002/smll.201801182

Abstract

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.

Keywords: Schottky contacts; graphene; graphene-silicon heterostructure photodetectors; graphene-silicon hybrid photodetectors; heterostructures; hybridstructures; photodetectors.