title: High-performance graphene-quantum-dot photodetectors.
abstract: Graphene quantum dots (GQDs) have received much attention due to their novel phenomena of charge transport and light absorption/emission. The optical transitions are known to be available up to ~6 eV in GQDs, especially useful for ultraviolet (UV) photodetectors (PDs). Thus, the demonstration of photodetection gain with GQDs would be the basis for a plenty of applications not only as a single-function device in detecting optical signals but also a key component in the optoelectronic integrated circuits. Here, we firstly report high-efficient photocurrent (PC) behaviors of PDs consisting of multiple-layer GQDs sandwiched between graphene sheets. High detectivity (>10(11) cm Hz(1/2)/W) and responsivity (0.2 ~ 0.5 A/W) are achieved in the broad spectral range from UV to near infrared. The observed unique PD characteristics prove to be dominated by the tunneling of charge carriers through the energy states in GQDs, based on bias-dependent variations of the band profiles, resulting in novel dark current and PC behaviors.
authors.affiliation: 1] Department of Applied Physics and Institute of Natural Sciences, College of Applied Science, Kyung Hee University, Yongin 446-701, Korea [2].
authors.forename: Chang Oh
authors.initials: CO
authors.lastname: Kim
authors.affiliation: 1] Advanced Development Department, Samsung Electronics Co., Ltd, Yongin 446-711, Korea [2].
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Hwang
authors.affiliation: 1] Department of Applied Physics and Institute of Natural Sciences, College of Applied Science, Kyung Hee University, Yongin 446-701, Korea [2].
authors.forename: Sung
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, College of Applied Science, Kyung Hee University, Yongin 446-701, Korea.
authors.forename: Dong Hee
authors.initials: DH
authors.lastname: Shin
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, College of Applied Science, Kyung Hee University, Yongin 446-701, Korea.
authors.forename: Soo Seok
authors.initials: SS
authors.lastname: Kang
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, College of Applied Science, Kyung Hee University, Yongin 446-701, Korea.
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, College of Applied Science, Kyung Hee University, Yongin 446-701, Korea.
authors.forename: Chan Wook
authors.initials: CW
authors.lastname: Jang
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, College of Applied Science, Kyung Hee University, Yongin 446-701, Korea.
authors.forename: Ju Hwan
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, College of Applied Science, Kyung Hee University, Yongin 446-701, Korea.
authors.forename: Kyeong Won
authors.initials: KW
authors.lastname: Lee
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, College of Applied Science, Kyung Hee University, Yongin 446-701, Korea.
authors.forename: Suk-Ho
authors.initials: SH
authors.lastname: Choi
authors.affiliation: SKKU Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Euyheon
authors.initials: E
authors.lastname: Hwang