The characteristics of Cu(In, Ga)Se 2 thin-film solar cells by bandgap grading
- 주제(키워드) Bandgap grading , CIGSe , Defect , Solar cell , Surface potential
- 등재 SCIE, SCOPUS, KCI등재
- 발행기관 Korean Society of Industrial Engineering Chemistry
- 발행년도 2019
- URI http://www.dcollection.net/handler/ewha/000000159937
- 본문언어 영어
- Published As http://dx.doi.org/10.1016/j.jiec.2019.04.010
- 저작권 이화여자대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
We investigated the characteristics of Cu(In, Ga)Se 2 solar cells with bandgap (E g ) grading. Two precursor types were employed: Mo/Cu 0.75 Ga 0.25 /In/Ga 2 Se 3 (CIGSe-1) and Mo/Cu/In/Ga 2 Se 3 (CIGSe-2). In CIGSe-1, the range of depths with a high Ga content is wider than that in CIGSe-2; thus, the region in which the main electron-trapping clusters and high-population deep donor defects can form is larger, and the defect density is higher. In the defect energy level range, various other defects and defect clusters exist with a defect density of 2.83 × 10 15 cm −3 within the CIGS-1 absorber layer and 2.37 × 10 15 cm −3 within the CIGS-2 absorber layer. The average efficiency values are 5.71% for CIGSe-1 and 6.82% for CIGSe-2. Additionally, the average V OC deficit (E g /q − V OC ) values are 0.758 V for CIGSe-1 and 0.731 V for CIGSe-2. As a result, in the 7 CIGSe-2 samples, the open-circuit voltage and efficiencies are improved. Thus, it is demonstrated that appropriate E g grading in a CIGSe layer with a wider E g on the back surface can result in improved performance. © 2019 The Korean Society of Industrial and Engineering Chemistry
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