New ternary compounds cualx2 (x = te, se) buffer layers: large band gap

I.III.VI2 chalcopyrites received serious attention as attractive candidates as active layers in polycristalline thin films solar cells. In the ternary I.III.VI2 family, CuAlX2 appears as good candidates as buffer layers in Cu(In, Ga)Sc2 based solar cells. These films can be obtained by annealing of Cu/Al/Sc… sequentially deposited structure. The annealed films are characterised by XPS, XRD, SEM. Microprobe analysis and then they are optically et electrically characterized. It is shown that ternary compounds crystallized in the expected chalcopyrite structure are obtained. The optical and electrical properties of the films confirms that they are good candidates to replace CdS buffer layers in solar cells.