1. Faculty of Science and Technology, Princess of Naradhiwas University, Narathiwat, Thailand
2. Surface Technology Research Unit (STRU), Faculty of Science and Technology, Nakhon Si Thammarat Rajabhat University, Nakhon Si Thammarat, Thailand
3. Division of Physical Science (Physics), Faculty of Science, Prince of Songkla University, Songkhla, Thailand
4. Center of Excellence in Nanotechnology for Energy (CENE), Songkhla, Thailand