Chen Shih-Chen, Wang Sheng-Wen, Kuo Shou-Yi, Juang Jenh-Yih, Lee Po-Tsung, Luo Chih Wei, Wu Kaung-Hsiung, Kuo Hao-Chung
Department of Electrophysics, National Chiao-Tung University, Hsinchu, Taiwan.
Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu, Taiwan.
Nanoscale Res Lett. 2017 Dec;12(1):208. doi: 10.1186/s11671-017-1993-0. Epub 2017 Mar 21.
In this work, aiming at developing a rapid and environmental-friendly process for fabricating CuIn Ga Se (CIGS) solar cells, we demonstrated the one-step selenization process by using selenium vapor as the atmospheric gas instead of the commonly used HSe gas. The photoluminescence (PL) characteristics indicate that there exists an optimal location with superior crystalline quality in the CIGS thin films obtained by one-step selenization. The energy dispersive spectroscopy (EDS) reveals that the Ga lateral distribution in the one-step selenized CIGS thin film is intimately correlated to the blue-shifted PL spectra. The surface morphologies examined by scanning electron microscope (SEM) further suggested that voids and binary phase commonly existing in CIGS films could be successfully eliminated by the present one-step selenization process. The agglomeration phenomenon attributable to the formation of MoSe layer was also observed. Due to the significant microstructural improvement, the current-voltage (J-V) characteristics and external quantum efficiency (EQE) of the devices made of the present CIGS films have exhibited the remarkable carrier transportation characteristics and photon utilization at the optimal location, resulting in a high conversion efficiency of 11.28%. Correlations between the defect states and device performance of the one-step selenized CIGS thin film were convincingly delineated by femtosecond pump-probe spectroscopy.
在这项工作中，旨在开发一种快速且环保的制备铜铟镓硒（CIGS）太阳能电池的工艺，我们展示了通过使用硒蒸气作为气氛气体而非常用的H₂Se气体的一步硒化工艺。光致发光（PL）特性表明，在通过一步硒化获得的CIGS薄膜中存在具有优异晶体质量的最佳位置。能量色散光谱（EDS）显示，一步硒化的CIGS薄膜中的Ga横向分布与蓝移的PL光谱密切相关。通过扫描电子显微镜（SEM）检查的表面形貌进一步表明，CIGS薄膜中常见的空洞和二元相可以通过当前的一步硒化工艺成功消除。还观察到了归因于MoSe层形成的团聚现象。由于显著的微观结构改善，由当前CIGS薄膜制成的器件的电流-电压（J-V）特性和外部量子效率（EQE）在最佳位置表现出显著的载流子传输特性和光子利用率，从而实现了11.28%的高转换效率。飞秒泵浦-探测光谱令人信服地描绘了一步硒化的CIGS薄膜的缺陷态与器件性能之间的相关性。
