Abstract: A method for manufacturing a copper-free CdTe based thin film solar cell device, comprising the following steps: a) providing a substrate at least comprising a front electrode, b) depositing a CdTe based absorber layer, c) performing an activation treatment, d) applying a X-halogen to the CdTe based absorber layer, wherein X is selected out of a group consisting of P, As, Sb and V; e) performing a thermal treatment after step d) and f) depositing a back contact, characterized in that, the thermal treatment in step e) is performed before step f) and at temperatures in the range of 40° C. to 120° C. in inert atmosphere or vacuum for a duration in the range of 10 minutes to 60 minutes.

Abstract: A method for manufacturing a CdTe based thin film solar cell device with a graded refractive index profile within the CdTe-based absorber layer. The method comprises the following steps: a) providing a transparent substrate comprising a front electrode, b) forming a doped CdTe based absorber layer on the substrate, c) performing an activation treatment after step b). The doped CdTe based absorber layer in step b) is formed as a doped CdTe based absorber layer stack comprising a first and a second layer. The first layer is formed as a first doping element containing layer comprising vanadium as the first doping element by depositing a first doping element-rich layer and subsequently depositing a CdSe layer or a CdSeTe layer, or by depositing a CdSe layer or a CdSeTe layer each doped with the first doping element. The second layer is formed by depositing a CdTe layer. A CdTe based thin film solar cell device with a graded refractive index profile.