title: Energy transfer from an individual silica nanoparticle to graphene quantum dots and resulting enhancement of photodetector responsivity.
abstract: Förster resonance energy transfer (FRET), referred to as the transfer of the photon energy absorbed in donor to acceptor, has received much attention as an important physical phenomenon for its potential applications in optoelectronic devices as well as for the understanding of some biological systems. If one-atom-thick graphene is used for donor or acceptor, it can minimize the separation between donor and acceptor, thereby maximizing the FRET efficiency (EFRET). Here, we report first fabrication of a FRET system composed of silica nanoparticles (SNPs) and graphene quantum dots (GQDs) as donors and acceptors, respectively. The FRET from SNPs to GQDs with an EFRET of ∼78% is demonstrated from excitation-dependent photoluminescence spectra and decay curves. The photodetector (PD) responsivity (R) of the FRET system at 532 nm is enhanced by 10(0)∼10(1)/10(2)∼10(3) times under forward/reverse biases, respectively, compared to the PD containing solely GQDs. This remarkable enhancement is understood by network-like current paths formed by the GQDs on the SNPs and easy transfer of the carriers generated from the SNPs into the GQDs due to their close attachment. The R is 2∼3 times further enhanced at 325 nm by the FRET effect.
authors.affiliation: Department of Applied Physics and Institute of Natural Sciences, College of Applied Science, 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, 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: Jungkil
authors.initials: J
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: 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: 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: Dae Hun
authors.initials: DH
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: Jung Hyun
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: Suk-Ho
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Nano Science &Mechanics Engineering and Nanotechnology Research Center, Konkuk University, Chungju, Chungbuk 380-701, Korea.
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Hwang