Rapid quantitative analysis of elemental composition and depth profile of Cu(In,Ga)Se2 thin solar cell film using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is reported as a method for rapid quantitative analysis of elemental composition and depth profile of Cu(In,Ga)Se2 (CIGS) thin film. A calibration model considering compositional grading over depth was developed and verified with test samples. The results from eight test samples showed that the average concentration of Cu, In, Ga and Se could be predicted with a root mean square error of below 1% and a relative standard deviation of also below 1%. The depth profile of each constituent element of CIGS predicted by LIBS was close to those by Auger electron spectroscopy and secondary ion mass spectrometry. The average ablation depth per pulse during depth profiling was about 100 nm.