Crystalline ordered states of CuIn<sub>1鈭?span style='font-style: italic'>xsub>Ga<sub>xsub>Se<sub>2sub> (x聽=聽0, 0.3, and 1.0) thin-films on different substrates investigated by Raman scattering spectroscopy
- 作者：A.R. Jeong<sup>asup> ; W. Jo<sup>asup><sup> ; sup><sup>wmjo@ewha.ac.krsup> ; M. Song<sup>asup> ; S. Yoon<sup>asup><sup> ; sup><sup>bsup>
- 关键词：Cu(In ; Ga)Se2 ; Raman scattering spectroscopy ; Ordered states ; Substrate dependence
- 刊名：Materials Chemistry and Physics
- 出版年：2012
- 期刊代码：58_02540584
- 类别：ms
- 出版时间：15 June, 2012
- 卷：134
- 期：2-3
- 页码：1030-1035
- 文件大小：1136 K
摘要
Structural properties of Cu(In,Ga)Se<sub>2sub> absorber layers have been examined for photovoltaic applications. Thin-films with three different chemical compositions, CuInSe<sub>2sub> (CIS), Cu(In,Ga)Se<sub>2sub> (CIGS) and CuGaSe<sub>2sub> (CGS), were grown by co-evaporation on two kinds of substrates: Mo-coated soda-lime glass and bare soda-lime glass. Intriguing morphology and grain-growth behaviors were found in the surface of the films. X-ray diffraction of the films exhibited phase formation of the stoichiometric chalcopyrite phase of the materials while signs of secondary phases like Cu<sub>2sub>Se and Cu-Se<sub>2sub> were also observed. The optical transmittance of the films was measured to obtain their optical bandgaps, which were well matched with the bulk values of CIS, CIGS, and CGS, which are 1.1, 1.4, and 1.7聽eV, respectively. Using Raman scattering spectroscopy, the A<sub>1sub> mode was observed to shift from 177聽cm<sup>鈭?sup> for CIS to 189聽cm<sup>鈭?sup> for CGS as the Ga content increased. The films on Mo substrates are likely to have secondary phases, which is not the case for soda-lime glass. An indication of the formation of the CuAu structure is obtained from the CIS thin-films.