title: Light-induced negative differential resistance in graphene/Si-quantum-dot tunneling diodes.
abstract: One of the interesing tunneling phenomena is negative differential resistance (NDR), the basic principle of resonant-tunneling diodes. NDR has been utilized in various semiconductor devices such as frequency multipliers, oscillators, relfection amplifiers, logic switches, and memories. The NDR in graphene has been also reported theoretically as well as experimentally, but should be further studied to fully understand its mechanism, useful for practical device applications. Especially, there has been no observation about light-induced NDR (LNDR) in graphene-related structures despite very few reports on the LNDR in GaAs-based heterostructures. Here, we report first observation of LNDR in graphene/Si quantum dots-embedded SiO2 (SQDs:SiO2) multilayers (MLs) tunneling diodes. The LNDR strongly depends on temperature (T) as well as on SQD size, and the T dependence is consistent with photocurrent (PC)-decay behaviors. With increasing light power, the PC-voltage curves are more structured with peak-to-valley ratios over 2 at room temperature. The physical mechanism of the LNDR, governed by resonant tunneling of charge carriers through the minibands formed across the graphene/SQDs:SiO2 MLs and by their nonresonant phonon-assisted tunneling, is discussed based on theoretical considerations.
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, 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, 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, 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, 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, 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, Kyung Hee University, Yongin 446-701, Korea.
authors.forename: Dae Hun
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, Kyung Hee University, Yongin 446-701, Korea.
authors.forename: Sung
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, 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