Iype, Mercy, Shaji Varghese, and E.J. Mathew. “Determination of the Energy Band Gap and Absorption Coefficient of Thin Films of Chemically Deposited Lead Sulphide, Copper Sulphide and Multilayer Lead Sulphide-Copper Sulphide Thin Films ”. Asian Journal of Chemistry 14, no. 2 (March 30, 2010): 927–933. Accessed November 29, 2024. https://asianpubs.org/index.php/ajchem/article/view/22186.