Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (35권1호 39-46)

A study on the properties of Cu$_2$ZnSnS$_4$ thin films prepared by rf magnetron sputtering process

RF Magnetron Sputtering법으로 제조한 Cu$_2$ZnSnS$_4$박막 특성에 관한 연구

이재춘;설재승;남효덕;배인호;김규호;

영남대학교 재료금속공학부;영남대학교 전기전자공학부;영남대학교 물리학과;

Abstract

$Cu_2$$ZnSnS_4$(CZTS) thin film is one of the candidate materials for the solar cell. It has an excellent optical absorption coefficient as well as appropriate 1.4~1.5eV band gap. The purpose of this study is replacing a half of high-cost Indium(In) atoms with low-cost Zinc(Zn) atoms and the other half with low-cost Tin(Sn) atoms in the lattice of CIS. Thin films were deposited on ITO glass substrates using a compact target which were made by $Cu_2$S, ZnS, SnS$_2$ powder at room temperature by rf magnetron sputtering and were annealed in the atmosphere of Ar and $S_2$(g). We investigated potentialities of a low-cost material for the solar cell by measuring of thin film composition, the structure and optical properties. We could get an appropriate $Cu_2$$ZnSnS_4$ composition. Structure was coarsened with increasing temperature and (112), (200), (220), (312) planes appeared to conform to all the reflection Kesterite structure. A (112) preferred orientation was advanced with increasing the annealing temperature as shown in the diffraction peaks of the CIS cells and was available for photovoltaic thin film materials. The band gap increased from 1.51 to 1.8eV as the annealing temperature increased. The optical absorption coefficient of the thin film was about $10^4$$cm^{-1}$.

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