Jang Yun Jung, Lee Jihye, Jeong Jeung-Hyun, Lee Kang-Bong, Kim Donghwan, Lee Yeonhee
Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 02792, Korea.
Photoelectronic Hybrid Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea.
J Nanosci Nanotechnol. 2018 May 1;18(5):3548-3556. doi: 10.1166/jnn.2018.14646.
To enhance the conversion performance of solar cells, a quantitative and depth-resolved elemental analysis of photovoltaic thin films is required. In this study, we determined the average concentration of the major elements (Cu, In, Ga, and Se) in fabricated Cu(In,Ga)Se2 (CIGS) thin films, using inductively coupled plasma atomic emission spectroscopy, X-ray fluorescence, and wavelengthdispersive electron probe microanalysis. Depth profiling results for CIGS thin films with different cell efficiencies were obtained using secondary ion mass spectrometry and Auger electron spectroscopy to compare the atomic concentrations. Atom probe tomography, a characterization technique with sub-nanometer resolution, was used to obtain three-dimensional elemental mapping and the compositional distribution at the grain boundaries (GBs). GBs are identified by Na increment accompanied by Cu depletion and In enrichment. Segregation of Na atoms along the GB had a beneficial effect on cell performance. Comparative analyses of different CIGS absorber layers using various analytical techniques provide us with understanding of the compositional distributions and structures of high efficiency CIGS thin films in solar cells.
为提高太阳能电池的转换性能，需要对光伏薄膜进行定量且深度分辨的元素分析。在本研究中，我们使用电感耦合等离子体原子发射光谱法、X射线荧光光谱法和波长色散电子探针微分析法，测定了制备的Cu(In,Ga)Se2（CIGS）薄膜中主要元素（铜、铟、镓和硒）的平均浓度。使用二次离子质谱法和俄歇电子能谱法获得了不同电池效率的CIGS薄膜的深度剖析结果，以比较原子浓度。原子探针断层扫描是一种具有亚纳米分辨率的表征技术，用于获得三维元素映射和晶界（GBs）处的成分分布。通过钠的增加以及铜的耗尽和铟的富集来识别晶界。钠原子沿晶界的偏析对电池性能有有益影响。使用各种分析技术对不同的CIGS吸收层进行比较分析，使我们能够了解太阳能电池中高效CIGS薄膜的成分分布和结构。
