CdTe thin film solar cells with ZnSe buffer layer

We investigate CdTe based solar cells fabricated with an unconventional structure which includes a Mo thin film deposited by sputtering as back contact and a ZnSe film deposited by evaporation as buffer layer. The use of window materials like the ZnSe which present wider band gap than CdS, could lead to enhancement in the photocurrent. Solar cells with structure Mo/CdTe/ZnSe/ZnO were fabricated. The ZnO layer was deposited by reactive evaporation and the CdTe layer was grown by CSS method. The preliminary results obtained with this type of cells are: J_sc= 17.2 mA/cm². Voc=0.6V, F.F=0.57 and η=5.9% with irradiance of 100 mW/cm². Solar cells fabricated using CdS buffer layers deposited by CBD on a CdTe substrate, prepared under the same conditions used in the fabrication of the Mo/CdTe/ZnSe/ZnO cells, gave the following results: Jsc = 18.9 mA/cm² V∝=0.62V, F.F=0.59 and η=6.9%.