Abstract
We use plane wave method to study the electronic structure of II-VI semiconductor and Mn-doped CdS. II-VI semiconductors: Zn(x)Cd(1-x)S and CdS(1-x)Se(x) having widely light emitting spectrum are promising materials of light emitting diodes. Mn-doped CdS is material for diluted magnetic semiconductors which is potential spintronics devices. We discuss the concentration dependent physics such as lattice and band gap in Zn(x)Cd(1-x)S and CdS(1-x)Se(x), and the magnetic property in Mn-doped CdS.