title: Photo-induced Doping in GaN Epilayers with Graphene Quantum Dots.
abstract: We demonstrate a new doping scheme where photo-induced carriers from graphene quantum dots (GQDs) can be injected into GaN and greatly enhance photoluminescence (PL) in GaN epilayers. An 8.3-fold enhancement of PL in GaN is observed after the doping. On the basis of time-resolved PL studies, the PL enhancement is attributed to the carrier transfer from GQDs to GaN. Such a carrier transfer process is caused by the work function difference between GQDs and GaN, which is verified by Kelvin probe measurements. We have also observed that photocurrent in GaN can be enhanced by 23-fold due to photo-induced doping with GQDs. The improved optical and transport properties from photo-induced doping are promising for applications in GaN-based optoelectronic devices.
authors.affiliation: Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li, Taiwan.
authors.forename: T N
authors.initials: TN
authors.lastname: Lin
authors.affiliation: Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li, Taiwan.
authors.forename: M R
authors.initials: MR
authors.lastname: Inciong
authors.affiliation: Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li, Taiwan.
authors.forename: S R M S
authors.initials: SR
authors.lastname: Santiago
authors.affiliation: Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li, Taiwan.
authors.forename: T W
authors.initials: TW
authors.lastname: Yeh
authors.affiliation: Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li, Taiwan.
authors.forename: W Y
authors.initials: WY
authors.lastname: Yang
authors.affiliation: Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li, Taiwan.
authors.forename: C T
authors.initials: CT
authors.lastname: Yuan
authors.affiliation: Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li, Taiwan.
authors.forename: J L
authors.initials: JL
authors.lastname: Shen
authors.affiliation: Department of Photonic and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsin-Chu, Taiwan.
authors.forename: H C
authors.initials: HC
authors.lastname: Kuo
authors.affiliation: Department of Electronic Engineering, Chung Yuan Christian University, Chung-Li, Taiwan.|Adavanced Optoelectronic Technology Inc., Hsin-Chu, Taiwan.
authors.forename: C H
authors.initials: CH
authors.lastname: Chiu