Yoo Hyesun, Jang Jun Sung, Shin Seung Wook, Lee Jiwon, Kim JunHo, Kim Dong Myeong, Lee In Jae, Lee Byeong Hoon, Park Jongsung, Kim Jin Hyeok
Optoelectronic Convergence Research Center and Department of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of Korea.
Future Agricultural Research Division, Rural Research Institute, Korea Rural Community Corporation, Ansan-Si 15634, Republic of Korea.
ACS Appl Mater Interfaces. 2021 Mar 24;13(11):13425-13433. doi: 10.1021/acsami.1c01307. Epub 2021 Mar 11.
Point defect engineering in CuZnSnSe (CZTSe) thin films is the main issue to improve its device performance. This study reveals the correlation between the reaction pathway and the point defects in the CZTSe film. The reaction pathway from a metallic precursor (Mo/Zn/Sn/Cu) to a kesterite CZTSe film is varied by changing the annealing process. The synthesized CZTSe films under different reaction pathways induce different device performances with different defect energy levels, although all CZTSe films have similar structural and optical properties ( ∼ 1.0 eV). The admittance spectroscopy demonstrates the correlations between point defect types (V, Zn, Zn, Cu, and V) and the reaction pathways for the formation of CZTSe films. The different growth rates of binary selenides, such as ZnSe and/or Sn-Se phases, during the annealing process are especially strongly related to the formation of point defects, leading to the different open-circuit voltages (396-451 mV) and fill factors (51-65%). The results of this study suggest that controlling the reaction pathway is an effective approach to adjust the formation of defects in the kesterite CZTSe film as well as to fabricate high-performance solar cell devices.
铜锌锡硒（CZTSe）薄膜中的点缺陷工程是提高其器件性能的主要问题。本研究揭示了CZTSe薄膜中反应路径与点缺陷之间的相关性。通过改变退火工艺，从金属前驱体（Mo/Zn/Sn/Cu）到硫锡铜矿CZTSe薄膜的反应路径会发生变化。尽管所有CZTSe薄膜都具有相似的结构和光学性质（约1.0 eV），但在不同反应路径下合成的CZTSe薄膜会因不同的缺陷能级而导致不同的器件性能。导纳谱证明了点缺陷类型（V、Zn、Zn、Cu和V）与CZTSe薄膜形成的反应路径之间的相关性。在退火过程中，二元硒化物（如ZnSe和/或Sn-Se相）的不同生长速率与点缺陷的形成尤其密切相关，导致不同的开路电压（396 - 451 mV）和填充因子（51 - 65%）。本研究结果表明，控制反应路径是调整硫锡铜矿CZTSe薄膜中缺陷形成以及制造高性能太阳能电池器件的有效方法。
