| 학회 |
한국재료학회 |
| 학술대회 |
2013년 봄 (05/23 ~ 05/24, 여수 엠블호텔(THE MVL)) |
| 권호 |
19권 1호 |
| 발표분야 |
C. 에너지/환경 재료(Energy and Environmental Materials) |
| 제목 |
Effect of Post-annealing on the ZnS/Cu(In,Ga)Se2 Solar Cells: Band Alignment at the ZnS/Cu(In,Ga)Se2 Interface |
| 초록 |
Cu(In,Ga)Se2 (CIGS) thin-film solar cells show greater than 20% efficiency. The typical structure of high-efficiency CIGS solar cells is n-ZnO/i-ZnO/CdS/ CIGS/Mo. For environmental considerations, the Cd element of CdS should be removed. Moreover, the short wavelength response of CdS/CIGS solar cells is limited by the narrow band gap of CdS (≈ 2.42 eV). To overcome these disadvantages of CdS/CIGS solar cells, many groups have studied various Cd-free materials over the past decade. At present, ZnS film as a Cd-free buffer layer is the most promising material. In laboratory scale, small-area ZnS/CIGS solar cell has achieved up to 19.7% efficiency. In commercial line, ZnS/CIGS solar modules have realized up to 17% efficiency. By the way, ZnS/CIGS solar cells still shows lower efficiency than CdS/CIGS solar cells. There are many factors that make it difficult to create ZnS/CIGS solar cells with efficiency levels that match those of CdS/CIGS solar cells. Most of all, there exists a large energy barrier to hinder charge carrier transport at the ZnS/CIGS interface due to large bandgap of ZnS. Unfortunately, it is hard to directly measure the state of ZnS/CIGS interface. The issue made heterointerface studies controversial. Thus, it is critical to define the conditions of ZnS/CIGS interface. Additionally, a post-annealing process is widely used to control the conditions of interface. In this study, we tried to observe exactly the conditions of ZnS/CIGS interface using REELS/UPS tool and investigate the effect of post-annealing on the cell performance. |
| 저자 |
신동협, 김승태, 김지혜, 신영민, 정광선, 권혁상, 안병태
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| 소속 |
KAIST 신소재공학 |
| 키워드 |
ZnS; Cu(In; Ga)Se2; post annealing; solar cell
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| E-Mail |
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