Optical Properties and Thermodynamic Function Properties of Undoped and Co-Doped $Zn_{0.5}Cd_{0.5}Al_{2}Se_{4}$ Single Crystals

$Zn_{0.5}Cd_{0.5}Al_{2}Se_{4}$$Zn_{0.5}Cd_{0.5}Al_{2}Se_{4}$:$Co^{2+}$ 단결정의 광학적 특성과 열역학 함수 추정

  • Hyun, Seung-Cheol ;
  • Park, Hjung ;
  • Park, Kwang-Ho ;
  • Oh, Seok-Kyun ;
  • Kim, Hyung-Gon ;
  • Kim, Nam-Oh
  • 현승철 (성화대학 안경광학과) ;
  • 박현 (목포과학대학 자동차과) ;
  • 박광호 (동아인재대학 안경광학과) ;
  • 오석균 (한국기초과학지원연구소) ;
  • 김형곤 (조선이공대학 전기과) ;
  • 김남오 (조선이공대학 전기과)
  • Published : 2003.07.01

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.

Keywords

Entropy;Enthalpy;Heat capacity;Optical Energy Gap;Varshni equation;Single crystal

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