Mobile QR Code QR CODE : The Transactions of the Korean Institute of Electrical Engineers
Title Optical Properties and Thermodynamic Function Properties of Undoped and Co-Doped Zn_{0.5}Cd_{0.5}Al_{2}Se_{4} Single Crystals
Authors 현승철(Hyun, Seung-Cheol) ; 박현(Park, Hjung) ; 박광호(Park, Kwang-Ho) ; 오석균(Oh, Seok-Kyun) ; 김형곤(Kim, Hyung-Gon) ; 김남오(Kim, Nam-Oh)
Page pp.275-281
ISSN 1975-8359
Keywords Entropy ; Enthalpy ; Heat capacity ; Optical Energy Gap ; Varshni equation ; Single crystal
Abstract Zn_{0.5}Cd_{0.5}Al_{2}Se_{4} and Zn_{0.5}Cd_{0.5}Al_{2}Se_{4}:Co^{2+} single crystals were grown by CTR method. The grown single crystals have defect chalcopyrite structure with lattice constant a=5.5966 AA, c=10.8042 AA for the pure, a=5.6543 AA, c=10.8205 AA for the Co-doped single crystal, respectively. The optical energy band gap was given as indirect band gap. The optical energy band gap was decreased according to add of Co-impurity Temperature dependence of optical energy band gap was fitted well to the Varshni equation. From this relation, we can deduced the entropy, enthalpy and heat capacity. Also, we can observed the Co-impurity optical absorption peaks assigned to the Co^{2+} ion sited at the T_{d} symmetry lattice and we consider that they were attributed to the electron transitions between energy levels of ions.