1. Department of Electrical Engineering, Universitas Prima Indonesia, Medan, Indonesia
2. Nanomaterials for Renewable Energy Laboratory (NRE Lab), CV. Inovasi Teknologi Nano, Medan, Indonesia
3. Department of Industrial Engineering, Universitas Prima Indonesia, Medan, Indonesia
4. Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Sumatera Utara, Medan, Indonesia
5. Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia