[1] Khon Kaen Univ, Fac Sci, Mat Sci & Nanotechnol Program, Khon Kaen 40002, Thailand
[2] Khon Kaen Univ, Fac Sci, Dept Phys, Khon Kaen 40002, Thailand
[3] Khon Kaen Univ, Inst Nanomat Res & Innovat Energy IN RIE, Khon Kaen 40002, Thailand
[4] Srinakharinwirot Univ, Fac Sci, Dept Phys, Bangkok 10110, Thailand
[5] Phu Xuan Univ, Fac Technol & Business, Hue City, Vietnam
[6] NSTDA, Natl Nanotechnol Ctr NANOTEC, 111 Thailand Sci Pk, Pathum Thani 12120, Thailand