The Preparation of Alumina Particles Wrapped in Few-layer Graphene Sheets and Their Application to Dye-sensitized Solar Cells

Abstract

Center for Research Utilities, Yeungnam University, Gyongsan 712-749, KoreaReceived December 2, 2010, Accepted March 21, 2011Alumina particles wrapped in few-layer graphene sheets were prepared by calcining aluminum nitride powdersunder a mixed gas flow of carbon monoxide and argon. The graphene sheets were characterized by powder X-ray diffraction (XRD), Raman spectroscopy, electron energy loss spectroscopy, and high-resolution trans-mission electron microscopy. The few-layer graphene sheets, which wrapped around the alumina particles, didnot exhibit any diffraction peaks in the XRD patterns but did show three characteristic bands (D, G, and 2Dbands) in the Raman spectra. The dye-sensitized solar cell (DSSC) with the alumina particles wrapped in few-layer graphene sheets exhibited significantly improved overall energy-conversion efficiency, compared toconventional DSSC, due to longer electron lifetime. Key Words : Graphene sheets, Aluminum nitride, Carbon monoxide, Dye-sensitized solar cellIntroductionSince the first report on electrical properties of singlelayer graphene by Novoselov and Geim in 2004,