Impurity and self-diffusion related to the copper sublattice in CIGSe thin-film solar cells

该方案旨在全面表征Cu(In，Ga)Se2(CIGSe)层中的扩散过程，为进一步优化相应的薄膜太阳电池提供科学依据。计划中的研究既涉及铜的自扩散，也涉及杂质元素Ag和Na的扩散和溶解，它们可能被Cu亚晶格所容纳，对CIGSe技术非常重要。特别是，计划通过在多晶和单晶CI(G)Se层中的详细实验来阐明在项目第一阶段观察到的银和钠的异常扩散行为。将杂质扩散的性质与自扩散的性质进行比较，应该可以检测到所涉及的晶格缺陷，例如空位和晶界，并确定每种情况下的扩散机制。主要的实验方法是放射性示踪剂扩散剖面法，辅之以使用SIMS分析的质谱学测量。关于溶解度和分离的更多数据将通过使用原子探针分析在近原子尺度上进行检查而获得。

The proposal aims at the comprehensive characterization of diffusion processes in Cu(In,Ga)Se2 (CIGSe) layers, in order to provide a scientific basis for the further optimization of the corresponding thin-film solar cells. The scheduled investigations concern both Cu self-diffusion and the diffusion and solubility of the impurity elements Ag and Na, which are likely to be accommodated by the Cu sublattice and are of great importance for CIGSe technology. In particular, it is planned to elucidate - by elaborate experiments in poly- and monocrystalline CI(G)Se layers - the anomalous diffusion behaviour of Ag and Na that was observed during the first period of the project. Comparing the properties of impurity diffusion with those of self-diffusion should make it feasible to detect the lattice defects involved, such as, e.g., vacancies and grain boundaries, and to identify the diffusion mechanism in each case. The main experimental method is radiotracer diffusion profiling, which will be supplemented by mass-spectroscopic measurements using SIMS analysis. Additional data on solubility and segregation will be obtained by examinations on a near-atomic scale using atom-probe analysis.