1. Department of Electronics and Instrumentation Engineering, Velammal Engineering College, Chennai, India;
2. Opto-electronic Sensor Research Laboratory, TIFAC-CORE, Velammal Engineering College, Chennai, India
3. Velammal Engineering College, Chennai, India;
4. Centre for Sol-Gel Coatings, International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Hyderabad, India;