The authors have demonstrated large-area suspended graphene on GaN nanopillars predefined by nanosphere lithography and inductively coupled plasma etching. The graphene was successfully suspended over large areas without ripples and corrugations. Scanning electron microscopy, atomic force microscopy and micro-Raman spectroscopy were used to characterize the properties of the suspended graphene on nanopillars. The thermal properties of the suspended and supported graphene were investigated by varying the underlying GaN nanopilllar geometries from flat-top to sharp-cone morphologies and heating the resulting structures via irradiation with laser powers of 1.53 mW, 8.03 mW, and 16.19 mW. The heat transfer was effective even when the contact area between the suspended graphene and the supporting substrate was small, due to the high thermal conductivities of graphene and GaN. The extremely high thermal conductivity of the graphene can improve the thermal management in GaN-based high power electronic and optoelectronics devices, a critical factor for their long-term reliability.
Bibliographical noteFunding Information:
This research was supported by New & Renewable Energy R&D program (R0903962) under the Ministry of Knowledge Economy, Basic Science Research Program (2009-0088551 and 2010-0008242) through the National Research Foundation of Korea, and by the Carbon Dioxide Reduction and Sequestration Center, a 21st Century Frontier R&D Program funded by the Ministry of Education, Science and Technology. The work at UF is partially funded by an AFOSR MURI monitored by Gregg Jessen.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering
- Materials Chemistry