Impact of the selenisation temperature on the structural and optical properties of CZTSe absorbers
Impact of the selenisation temperature on the structural and optical properties of CZTSe absorbers
复制标题
DOI：
10.1016/j.solmat.2016.03.018
复制
发表时间：
2016-08-01
影响因子：
6.9
通讯作者：
Martin, R. W.
中科院分区：
文献类型：
--
作者：
Marquez-Prieto, J.;Yakushev, M. V.;Martin, R. W.
我们研究了在Mo/Glass衬底上沉积的Cu2ZnSnSe4(CZTSe)薄膜的结构和光谱分析，这些薄膜在450℃、500℃和550℃下进行了硒处理，用这些薄膜制成的太阳能电池在500℃下的硒处理效率高达7.4%。基于X射线衍射和拉曼光谱的结构分析表明，在450℃下处理的薄膜中存在SnSe2，而在更高温度下处理的薄膜中没有SnSe2。随着渗硒温度的升高，锡和硒的含量逐渐降低。用光致发光激发测量了4.2K下的带隙，测量了光致发光光谱的温度和激发强度的依赖关系，从而可以将观察到的发射带的复合机制识别为带到杂质和带到带的跃迁，并分析了它们随硒化温度变化的演变。最强的带间跃迁记录在500℃下硒化膜的光致发光光谱中，并且可以在6K到室温下观察到。讨论了薄膜的成分和结构变化及其对CZTSe和太阳电池光电性能的影响。(C)2016爱思唯尔B.V.保留所有权利。
We present structural and optical spectroscopy studies of thin films of Cu2ZnSnSe4 (CZTSe) with strong copper deficiency deposited on Mo/Glass substrates and selenised at 450, 500 or 550 degrees C. Solar cells fabricated from these films demonstrated efficiencies up to 7.4% for selenisation at 500 degrees C. Structural analysis based on X-ray diffraction and Raman spectroscopy revealed the presence of SnSe2 in the film selenised at 450 degrees C but not in the films selenised at higher temperatures. A progressive decrease of the Sn and Se content was observed as the selenisation temperature increased. Photoluminescence excitation was used to determine the bandgaps at 4.2 K. Detailed measurements of the temperature and excitation intensity dependencies of the photoluminescence spectra allow the recombination mechanisms of the observed emission bands to be identified as band-to-impurity and band-to-band transitions, and their evolution with selenisation temperature changes to be analysed. The strongest band-to-band transition is recorded in the PL spectra of the film selenised at 500 degrees C and can be observed from 6 K to room temperature. The compositional and structural changes in the films and their influence on the optoelectronic properties of CZTSe and solar cells are discussed. (C) 2016 Elsevier B.V. All rights reserved.