Kim Min Jung, Lee Jihye, Kim Seon Hee, Kim Haidong, Lee Kang-Bong, Lee Yeonhee
J Nanosci Nanotechnol. 2015 Oct;15(10):7722-6. doi: 10.1166/jnn.2015.11181.
Chalcopyrite Cu(In, Ga)Se2 (CIGS) thin films are well known as the next-generation solar cell materials notable for their high absorption coefficient for solar radiation, suitable band gap, and ability for deposition on flexible substrate materials, allowing the production of highly flexible and lightweight solar panels. To improve solar cell performances, a quantitative and depth-resolved elemental analysis of photovoltaic thin films is much needed. In this study, Cu(In, Ga)Se2 thin films were prepared on molybdenum back contacts deposited on soda-lime glass substrates via three-stage evaporation. Surface analyses via AES and SIMS were used to characterize the CIGS thin films and compare their depth profiles. We determined the average concentration of the matrix elements, Cu, In, Ga, and Se, using ICP-AES, XRF, and EPMA. We also obtained depth profiling results using TOF-SIMS, magnetic sector SIMS and AES, and APT, a sub-nanometer resolution characterization technique that enables three-dimensional elemental mapping. The SIMS technique, with its high detection limit and ability to obtain the profiles of elements in parallel, is a powerful tool for monitoring trace elements in CIGS thin films. To identify impurities in a CIGS layer, the distribution of trace elements was also observed according to depth by SIMS and APT.
黄铜矿Cu(In, Ga)Se2（CIGS）薄膜作为下一代太阳能电池材料而广为人知，其显著特点是对太阳辐射具有高吸收系数、合适的带隙以及能够沉积在柔性衬底材料上，从而能够生产出高度柔性且轻质的太阳能电池板。为了提高太阳能电池的性能，非常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，通过三步蒸发法在沉积于钠钙玻璃衬底上的钼背接触上制备了Cu(In, Ga)Se2薄膜。采用俄歇电子能谱（AES）和二次离子质谱（SIMS）进行表面分析，以表征CIGS薄膜并比较它们的深度分布。我们使用电感耦合等离子体原子发射光谱法（ICP - AES）、X射线荧光光谱法（XRF）和电子探针微分析（EPMA）来测定基体元素Cu、In、Ga和Se的平均浓度。我们还使用飞行时间二次离子质谱（TOF - SIMS）、磁扇形二次离子质谱和俄歇电子能谱以及原子探针断层扫描（APT，一种能够进行三维元素映射的亚纳米分辨率表征技术）获得了深度剖析结果。二次离子质谱技术具有高检测限且能够并行获取元素分布，是监测CIGS薄膜中痕量元素的有力工具。为了识别CIGS层中的杂质，还通过二次离子质谱和原子探针断层扫描观察了痕量元素随深度的分布情况。
