[1] Univ Negeri Malang, Dept Phys, Jalan Semarang 5, Malang 65145, Indonesia
[2] Univ Negeri Malang, PUI PT Ctr Adv Mat Renewable Energy, Jalan Semarang 5, Malang 65145, Indonesia
[3] Univ Gadjah Mada, Dept Phys, Bulaksumur 55281, Yogyakarta, Indonesia
[4] Kampus ITS Sukolilo, Inst Teknol Sepuluh Nopember, Dept Mat & Met Engn, Surabaya 60111, Indonesia