• Kim, Hyun-Woong
• Tarwal, Nilesh L.
• Woo, Jeong Min
• Oh, Se-I
• Rani, Janardhanan R.
• Lee, Sungbae
• Mun, Bongjin Simon
• Jang, Jae Hyung
• Kim, Ki-Jeong

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 similar to 2 mu m 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.

Topics

• impedance spectroscopy
• Carbon
• nanotube
• thin film
• electron diffraction
• transmission electron microscopy
• luminescence