Intrinsic point defects in off-stoichiometric Cu2ZnSnSe4: A neutron diffraction study
Intrinsic point defects in off-stoichiometric Cu2ZnSnSe4: A neutron diffraction study
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DOI：
10.1063/1.4997402
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发表时间：
2018-04-28
影响因子：
3.2
通讯作者：
Schorr, Susan
中科院分区：
文献类型：
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作者：
Gurieva, Galina;Rios, Laura Elisa Valle;Schorr, Susan
本文用中子粉衍射法对非化学计量比开斯特石型CZTSe的本征点缺陷进行了实验研究。我们发现在用固相反应合成的各种非化学计量比多晶粉末样品中，存在铜空位(V-Cu)、各种阳离子反位缺陷(铜-锌、锌-铜、锌-锡、锡-锌和铜-锌)以及间隙(铜-i、锌-i)。结果表明，非化学计量比CZTSe中存在的点缺陷符合非化学计量比类型模型，假定某些阳离子取代能解释电荷平衡。除了已知的非化学计量类型A-H外，还引入了新的类型(I-L)。首次提出了CZTSe方晶石型相的化学成分与本征点缺陷之间的关系。除了非化学计量比类型的特殊缺陷外，CZTSe相中总是存在铜/锌无序。在贫铜/富锌的CZTSe中，被认为是提供最佳光伏性能的成分，主要是铜空位、锌-铜和锌-锡反位。此外，该成分区域显示出最低程度的铜/锌无序。由AIP出版公司出版。
This work is an experimental study of intrinsic point defects in off-stoichiometric kesterite type CZTSe by means of neutron powder diffraction. We revealed the existence of copper vacancies (V-Cu), various cation anti site defects (Cu-Zn, Zn-Cu, Zn-Sn, Sn-Zn, and Cu-Zn), as well as interstitials (Cu-i, Zn-i) in a wide range of off-stoichiometric polycrystalline powder samples synthesized by the solid state reaction. The results show that the point defects present in off-stoichiometric CZTSe agree with the off-stoichiometry type model, assuming certain cation substitutions accounting for charge balance. In addition to the known off-stoichiometry types A-H, new types (I-L) have been introduced. For the very first time, a correlation between the chemical composition of the CZTSe kesterite type phase and the occurring intrinsic point defects is presented. In addition to the off-stoichiometry type specific defects, the Cu/Zn disorder is always present in the CZTSe phase. In Cu-poor/Zn-rich CZTSe, a composition considered as the one that delivers the best photovoltaic performance, mainly copper vacancies, Zn-Cu and Zn-Sn anti sites are present. Also, this compositional region shows the lowest degree of Cu/Zn disorder. Published by AIP Publishing.