Optimization of CBD-CdS physical properties for solar cell applications considering a MIS structure. (5th June 2016) - Vigil-Galán, O.
Abstract: While the standard interpretation treats CdS/CdTe, CdS/Cu(In, Ga)Se2 (CIGSe) and CdS/kesterites as p-n junctions, some recent reports suggest these solar cells operate rather as a Metal-Insulator-Semiconductor (MIS) structure. In this paper, we report results about the dependence of electrical, optical, morphological and structural properties of CBD-CdS on growth conditions in order to obtain the best layers to be used in solar cells according to the MIS model. In particular, CBD-CdS thin films were synthesized by changing the complexing agents in the bath solution, the Cd source and the nominal S/Cd ratio. In order to study the impact of the different CdS deposition approaches, CIGSe and CZTSe solar cells were processed. The influence of CdS:Cu as well as Cd sources such as Cd(NO3 )2 and CdSO4 on solar cell electrical parameters is studied. Graphical abstract: Highlights: CdS thin films synthesized by changing the complexing agents, the Cd source and the nominal S/Cd ratio are investigated. CdS:Cu showed an efficiency improvement in CIGSe solar cell in comparison with the non-doped one. By using Cd(NO3 )2 as Cd source in CdS deposition, an 8.03% CZTSe solar cell efficiency was achieved. Higher Voc values are obtained for thinner and more resistive CdS layers. It is demonstrated that CdS/CIGSe and CdS/CZTSe solar cells operate rather as a MIS structure.