Cross-characterization methods to obtain an “absolute” quantification of Cu(In,Ga)Se2 in-depth and at the surface

To improve the efficiencies of Cu(In,Ga)Se
₂
solar cells, a perfect knowledge of the absorber composition is an absolute necessity. In order to, we performed, either in-depth or at the surface, a coupling of cross-characterization methods including among others, XPS, SIMS and Nano-Auger. We present here the comparisons of quantitative results determined using each characterization technique, with a specific focus on key composition parameters: GGI (([Ga]/([Ga]+[In])) and CGI ([Cu]/([Ga]+[In])) ratios. With this multi-technique approach, a multiscale determination of those ratios has been obtained, from micrometer to nanometer dimensions.