Solar Energy Materials and Solar Cells, Vol.49, No.1, 249-260, 1997
Microstructural characterization of high-efficiency Cu(In,Ga)Se-2 solar cells
Microstructures of Cu(In,Ga)Se-2 (CIGS) thin-film solar cells with a MgF2/ITO/ZnO/CdS/ CIGS/Mo/glass structure were studied by a cross-sectional high resolution and analytical transmission electron microscopy (TEM). The Mo back contact, CIGS absorber and CdS buffer layer were deposited by rf-magnetron sputtering, physical vapor deposition (PVD) and chemical bath deposition (CBD), respectively. The interfaces between the CIGS absorber and the Mo back contact and between the CdS buffer layer and the CIGS absorber layer were investigated in detail. There were two layers al the CIGS/Mo interface. One was a MoSe2 layer and the other was an amorphous layer. The thickness of the interface layers depends on the deposition conditions of the Mo layers. The CdS-layer deposited by CBD was a mixture of cubic and hexagonal phases with large number of stacking faults. The {111} plane of cubic or {0001} plane of hexagonal CdS tends to be parallel to the {112} plane of CIGS.
Keywords:THIN-FILMS;CUINSE2