Affiliation: | a Department of Semiconductor Science and Technology, SPRC, Chonbuk National University, Jeonju 561-756, Republic of Korea b Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221005, U.P., India c Department of Ceramic Engineering, Institute of Technology, Banaras Hindu University, Varanasi 221005, U.P., India |