title: Uniform graphene quantum dots patterned from self-assembled silica nanodots.
abstract: Graphene dots precisely controlled in size are interesting in nanoelectronics due to their quantum optical and electrical properties. However, most graphene quantum dot (GQD) research so far has been performed based on flake-type graphene reduced from graphene oxides. Consequently, it is extremely difficult to isolate the size effect of GQDs from the measured optical properties. Here, we report the size-controlled fabrication of uniform GQDs using self-assembled block copolymer (BCP) as an etch mask on graphene films grown by chemical vapor deposition (CVD). Electron microscope images show that as-prepared GQDs are composed of mono- or bilayer graphene with diameters of 10 and 20 nm, corresponding to the size of BCP nanospheres. In the measured photoluminescence (PL) spectra, the emission peak of the GQDs on the SiO(2) substrate is shown to be at ∼395 nm. The fabrication of GQDs was supported by the analysis of the Raman spectra and the observation of PL spectra after each fabrication step. Additionally, oxygen content in the GQDs is rationally controlled by additional air plasma treatment, which reveals the effect of oxygen content to the PL property.
authors.affiliation: Department of Material Science and Engineering, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Jinsup
authors.initials: J
authors.lastname: Lee
authors.forename: Kyungho
authors.initials: K
authors.lastname: Kim
authors.forename: Woon Ik
authors.initials: WI
authors.lastname: Park
authors.forename: Bo-Hyun
authors.initials: BH
authors.lastname: Kim
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Park
authors.forename: Tae-Heon
authors.initials: TH
authors.lastname: Kim
authors.forename: Sungyool
authors.initials: S
authors.lastname: Bong
authors.forename: Chul-Hong
authors.initials: CH
authors.lastname: Kim
authors.forename: Geesung
authors.initials: G
authors.lastname: Chae
authors.forename: Myungchul
authors.initials: M
authors.lastname: Jun
authors.forename: Yongkee
authors.initials: Y
authors.lastname: Hwang
authors.forename: Yeon Sik
authors.initials: YS
authors.lastname: Jung
authors.forename: Seokwoo
authors.initials: S
authors.lastname: Jeon