CdS and Zn O,S grown by chemical bath deposition CBD are well established buffer materials for Cu In,Ga Se2 CIGS solar cells. As recently reported, a non contiguous coverage of CBD buffers on CIGS grains with 112 surfaces can be detected, which was explained in terms of low surface ener gies of the 112 facets, leading to deteriorated wetting of the chemical solutionon the CIGS surface. In the present contri bution, we report on the effect of air armealing of CIGS thin films prior to the CBD of CdS and Zn O,S layers. In cantrast to the growth on the as grown CIGS layers, these buffer layers grow densely on the annealed CIGS layer, even on grains with 112 surfaces. We explain the different growth behav ior by increased surface energies of CIGS grains due to the armealing step, i.e., due to oxidation of the CIGS surface. Reference solar cells were processed and completed by i ZnO ZnO Allayers for CdS and by Zn,Mg O ZnO Al for Zn O,S buffers. For solar cells with both, CdS and Zn O,S buffers, air annealed CIGS films with improved buffer cover age resulted in higher power conversion efficiencies, as com pared with the devices cantairring as grown CIGS layers.