Author/Authors :
Bنr، نويسنده , , M. and Ennaoui، نويسنده , , A. and Klaer، نويسنده , , J. and Sلez-Araoz، نويسنده , , R. and Kropp، نويسنده , , T. and Weinhardt، نويسنده , , L. and Heske، نويسنده , , C. and Schock، نويسنده , , H.-W. and Fischer، نويسنده , , Ch.-H. and Lux-Steiner، نويسنده , , M.C.، نويسنده ,
Abstract :
Recently, Cd-free wide-gap CuInS2-based ‘CIS’ thin film solar cells with a [Zn(S,O)/ZnS] bi-layer instead of a CdS buffer were developed, which (after post-annealing) showed comparable power conversion efficiencies as CdS-buffered references. To elucidate whether the heat treatment changes the electronic structure of the [Zn(S,O)/ZnS]/CIS heterointerface, which could explain the performance improvement, we have investigated corresponding structures by X-ray and UV photoelectron as well as optical spectroscopy before and after post-annealing. A heat-treatment-induced increase of the band bending in the CIS absorber could be identified, which correlates with an improved open circuit voltage of respective solar cells after post-annealing.
