Theoretical and computational exploration of electronic structure, optical properties, open circuit voltage, and toxicity of perovskites solar Cell:(Cs2SiX6, X = Cl, Br, and I) oleh Md. Hazrat Ali, Halima Khatun, M.S.S. Khan, Shuva Roy, Shubha Roy, Ridoy Hossain, Md. Robiul Mia, Ashiqur Rahman Khan, Syed Arfin Hussain, Md. Bayejid Hossen, Md. Barkat Ullah Khan, Abdul Kaiyum, Md Tauhidul Karim, Unesco Chakma, Ajoy Kumer