Moisture Condensation on Epitaxial Graphene upon Cooling
Muhammad Farooq Saleem,
Niaz Ali Khan,
Muhammad Javid,
Ghulam Abbas Ashraf,
Yasir A. Haleem,
Muhammad Faisal Iqbal,
Muhammad Bilal,
Peijie Wang,
Lei Ma
Affiliations
Muhammad Farooq Saleem
Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, Tianjin 300072, China
Niaz Ali Khan
Hubei Key Laboratory of Advanced Textile Materials & Application, Wuhan Textile University, Yangguang Road 1, Wuhan 430200, China
Muhammad Javid
Institute of Advanced Magnetic Materials, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310012, China
Ghulam Abbas Ashraf
Key Laboratory of Integrated Regulation and Resources Development on Shallow Lake, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
Yasir A. Haleem
Department of Physics, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan 64200, Pakistan
Muhammad Faisal Iqbal
Department of Physics, Riphah International University, Faisalabad 38000, Pakistan
Muhammad Bilal
College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
Peijie Wang
The Beijing Key Laboratory for Nano-Photonics and Nano-Structure, Department of Physics, Capital Normal University, Beijing 100048, China
Lei Ma
Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, Tianjin 300072, China
Condensation of moisture on the epitaxial graphene on 6H-SiC was observed below room temperature despite continuous nitrogen flow on the graphene surface. Raman peaks associated with ice were observed. A combination of peaks in the frequency range of 500–750 cm−1, along with a broad peak centered at ~1327 cm−1, were also observed and were assigned to airborne contaminants. The latter is more important since its position is in the frequency range where the defect-associated D band of graphene appears. This band can be easily misunderstood to be the D band of graphene, particularly when the Raman spectrum is taken below room temperature. This peak was even observed after the sample was brought back to room temperature due to water stains. This work highlights the importance of careful Raman investigation of graphene below room temperature and its proper insulation against moisture.
