title: Graphene oxide-phosphor hybrid nanoscrolls with high luminescent quantum yield: synthesis, structural, and X-ray absorption studies.
abstract: Highly luminescent graphene oxide (GO)-phosphor hybrid thin films with a maximum quantum yield of 9.6% were synthesized via a simple chemical method. An intense luminescence emission peak at 537 nm and a broad emission peak at 400 nm were observed from the GO-phosphor hybrid films. The maximum quantum yield of the emissions from the hybrid films was found to be 9.6%, which is 48 times higher than that of pristine GO films. The GO-phosphor hybrids were prepared via spin-coating and subsequent postannealing of the films, resulting in scrolling of the GO sheets. The resulting GO nanoscrolls exhibited a length of ∼2 μm with nanoscale interior cavities. Transmission electron microscopy and selected-area electron diffraction analyses revealed that the lattice structure of the tubular scrolls is similar to that of carbon nanotubes. While pristine GO films are p-type, in the GO-phosphor hybrids, the Fermi level shifted upward and fell between the HOMO-LUMO gap due to phosphor attachment via C-N bonding. The highly luminescent GO-phosphor hybrids will find important applications in graphene-based optoelectronic devices.
authors.forename: Janardhanan R
authors.initials: JR
authors.lastname: Rani
authors.forename: Se-I
authors.initials: SI
authors.lastname: Oh
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Woo
authors.forename: Nilesh L
authors.initials: NL
authors.lastname: Tarwal
authors.forename: Hyun-Woong
authors.initials: HW
authors.lastname: Kim
authors.forename: Bongjin Simon
authors.initials: BS
authors.lastname: Mun
authors.forename: Sungbae
authors.initials: S
authors.lastname: Lee
authors.affiliation: §Beamline Research Division, Pohang Accelerator Laboratory, Pohang, Kyungbuk 790-784, South Korea.
authors.forename: Ki-Jeong
authors.initials: KJ
authors.lastname: Kim
authors.forename: Jae-Hyung
authors.initials: JH
authors.lastname: Jang
keywords: X-ray absorption; carbon nanotubes; graphene oxide; nanoscrolls