Fluctuations in net doping and lifetime in Cu(In,Ga)Se2 solar cells

By extracting profiles perpendicular to the substrate from images obtained by electron-beam-induced current measurements on Cu(In,Ga)Se
₂
(CIGS) solar cells, fluctuations in the width of the space-charge region as well as in the diffusion length in the quasi-neutral region were studied. Devices with various solution-grown buffer layers as well as different [Ga]/([Ga]+[In]) ratios in the CIGS absorber were investigated. Complementary analyses by means of energy-dispersive X-ray spectrometry, and cathodoluminescence provide additional insight into the local optoelectronic and compositional properties of investigated cells.