Comparative atom probe study of Cu(In,Ga)Se2 thin-film solar cells deposited on soda-lime glass and mild steel substrates
Comparative atom probe study of Cu(In,Ga)Se2 thin-film solar cells deposited on soda-lime glass and mild steel substrates
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DOI：
10.1063/1.3665723
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发表时间：
2011-12-15
影响因子：
3.2
通讯作者：
Raabe, Dierk
中科院分区：
文献类型：
--
作者：
Choi, Pyuck-Pa;Cojocaru-Miredin, Oana;Raabe, Dierk
我们报告了在钠石灰玻璃和低碳钢衬底上沉积Cu(In,Ga)Se-2太阳能电池的比较研究，使用原子探针断层扫描结合二次离子质谱，x射线荧光，电流密度电压和外部量子效率测量。在钠石灰玻璃衬底和钢衬底上沉积的Cu(In,Ga)Se-2薄膜含有大量的Na杂质，并能提高开路电压和填充系数。利用原子探针层析成像，发现Na原子在晶界处偏析，并在体晶界和晶界处聚集。原子探针数据表明，Na-Cu点缺陷最有可能在晶界处形成，从而减少了补偿In-Cu点缺陷的数量，从而有助于提高电池效率。然而，对于钢衬底，Na对电池性能的积极影响被Fe杂质掺入Cu(In,Ga)Se-2薄膜所抵消。铁原子均匀地分布在晶粒内部，这表明铁在体中引入了点缺陷(C)， 2011年美国物理研究所。(doi: 10.1063/1.3665723)
We report on a comparative study of Cu(In,Ga)Se-2 solar cells deposited on soda-lime glass and mild steel substrates, using atom probe tomography in conjunction with secondary ion mass spectrometry, x-ray fluorescence, current density-voltage, and external quantum efficiency measurements. Cu(In,Ga)Se-2 films deposited on soda-lime glass substrates and on steel substrates with a NaF precursor layer on top of the Mo back contact contain a significant amount of Na impurities and yield an enhanced open circuit voltage and fill factor. Using atom probe tomography, Na atoms are found to be segregated at grain boundaries and clustered in both bulk and grain boundaries. The atom probe data indicate that Na-Cu point defects are most likely formed at grain boundaries, reducing the number of compensating In-Cu point defects and thus contributing to an enhanced cell efficiency. However, for steel substrates the positive effect of Na on the cell performance is counterbalanced by the incorporation of Fe impurities into the Cu(In,Ga)Se-2 film. Fe atoms are homogeneously distributed inside the grains suggesting that Fe introduces point defects in the bulk (C) 2011 American Institute of Physics. [doi:10.1063/1.3665723]