A Quantitative Analysis for CIGS Thin Films by Dynamic Secondary Ion Mass Spectrometry

Abstract

In these days, interesting novel applications in photovoltaics are focused on thin and flexible solar modules, especially in the fields of space, aeronautics, and mobile applications. Within the past years, many researchers have been studied the development of flexible and lightweight CIGS modules and especially the role and the determination of Na in CIGS films was frequently studied. However, CIGS thin films contain a little amount of Na like 0.1 %, so that depth profiles of Na in CIGS are very difficult to obtain by general analytical techniques. Dynamic SIMS has been widely used in an elemental analysis and a depth-profiling for a trace element existed on the surface because it is highly sensitive enough to detect small amount of ions at the level of ppm or ppb. There are various experimental conditions and factors to affect the SIMS depth profiling, such as primary ion, beam energy, beam current, raster size, surface roughness, position in the sample stage, and homogeneity of chemical composition of the sample, etc. Therefore, we evaluated Dynamic SIMS whether it is a suitable quantitative analysis technique for thin layer mixed with homogeneous bulk material such as CIGS. We have obtained a calibration curve to give the quantitative analysis information with low standard deviation.