Surface Cu depletion of Cu(In,Ga)Se2 films: An investigation by hard X-ray photoelectron spectroscopy
Surface Cu depletion of Cu(In,Ga)Se2 films: An investigation by hard X-ray photoelectron spectroscopy
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Cu(In,Ga)Se2 薄膜的表面铜耗尽：硬 X 射线光电子能谱研究
DOI：
10.1016/j.actamat.2009.04.029
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发表时间：
2009
期刊：
影响因子：
9.4
通讯作者：
I. Lauermann
中科院分区：
文献类型：
--
作者：
H. Mönig;C. Fischer;R. Caballero;C. Kaufmann;N. Allsop;M. Gorgoi;R. Klenk;H. Schock;S. Lehmann;M. Lux;I. Lauermann
在过去的15年里，人们一直在讨论多晶黄铜矿薄膜表面铜贫化的原因及其对相关太阳电池物理的影响。为了阐明这种贫铜表面层的成分和厚度，用硬X射线光电子能谱进行了随深度变化的成分分析。贫铜生长的Cu(In，Ga)Se2样品的数据指向亚纳米区域的表面层，该表面层完全缺乏铜。这一结果支持了其他作者的第一性原理计算提出的表面重建模型。对所研究样品的表面形貌分析证实了铜的贫化和表面的刻面相结合。理论分析表明，传统光电子能谱研究中发现的表观表面浓度比[Cu]/([In]+[Ga])=1/3可以用表面重构模型来解释。
The origin of surface Cu depletion of polycrystalline chalcopyrite thin films and its consequences for the physics of related solar cells have been discussed for the past 15 years. In order to shed light on the composition and thickness of this Cu-depleted surface layer, depth-dependent compositional analysis by hard X-ray photoelectron spectroscopy was performed. The data from Cu-poor grown Cu(In,Ga)Se2samples point to a surface layer in the sub-nanometer regime, which is completely depleted of Cu. This result supports the surface reconstruction model proposed by first-principles calculations by other authors. Analysis of the surface morphology of the investigated samples confirms the conjunction of Cu depletion and faceting of the surface. Theoretical considerations show that the apparent surface concentration ratio of [Cu]/([In]+[Ga])=1/3 found by conventional photoelectron spectroscopy studies can be explained by the surface reconstruction model.