Reproducibility of CIGS thin film analysis by laser-induced breakdown spectroscopy

Abstract

The reproducibility of an elemental analysis of thin CIGS solar cell films by laser-induced breakdown spectroscopy (LIBS) is assessed. A Q-switched Nd:YAG laser (lambda = 532 nm, tau = 5 ns, top-hat profile) and an ICCD detector were used for the LIBS measurements. It was shown that the concentration ratios and depth profile of a CIGS sample with unknown composition could be predicted with high precision by using the calibration curves generated with reference CIGS samples. The spot-to-spot relative standard deviation of 1.4% could be achieved for (Ga + In)/Cu at the gate delay of 0.1 ms condition, demonstrating that LIBS can be applied for real time monitoring of the elemental composition of CIGS thin films.