Estudio comparativo de la degradación de celdas solares de CdTe con CdS procesado por CBD y CSVT

Abstract

In this work we presented a comparative study of the degradation of thin films solar cells of CdS/CdTe, with the Cadmium Sulfide (CdS) deposited by Chemical Bath Deposition (CdS-CBD) and Closed Space Vapor Transport (CdS-CSVT) techniques, in both cases the Cadmium Telluride (CdTe) thin film was deposited by CSVT and both the CdS and CdTe were submitted at the same heat treatment (TT) with Cadmium Chloride (CdCl$_{2})$. In the CdS-CBD solar cells, the CdS was deposited at different relations of sulfur with respect to cadmium (S/Cd) in chemical bath; wherever the CdS-CSVT solar cells, the CdS was deposited at different times for obtained the similar thickness to CdS-CBD solar cells. The initial photovoltaic efficiency of the best CdS-CBD solar cells was 12.3% for the sample with relation S/Cd=5:1 and the initial photovoltaic efficiency of the best CdS-CSVT solar cells was 11.2% for CdS sample with the thickness of 140 nm before TT-CdCl$_{2}$. The solar cells CdS-CDB and CdS-CSVT obtained 6 years ago were characterization regularly by optical transmittance, photoluminescence, spectral quantum efficiency (QE) and current function voltage (I vs. V); the measurements shows the degradation in these photovoltaic devices submitted at exposed to the weather.