Temperature Dependence of Energy Gap and Thermodynamic Function Properties of Undoped and Co-doped $Cd_{4}GeSe_{6}$ Single Crystals by Chemical Transport Reaction Method

화학수송법으로 성장한 $Cd_{4}GeSe_{6}$ 및 $Cd_{4}GeSe_{6}:Co$ 단결정에서 Energy Gap의 온도의존성 및 열역학함수 추정

In this work $Cd_{4}GeSe_{6}$ and $Cd_{4}GeSe_{6}:Co^{2+}$ single crystals were grown by the chemical transport reaction method and the structure of $Cd_{4}GeSe_{6}$ and $Cd_{4}GeSe_{6}:Co$ single crystals were monoclinic structure. The temperature dependence of optical energy gap was fitted well to Varshni equation. Also, the entropy, enthalpy and heat capacity were deduced from the temperature dependence of optical energy gap.