PREPARATION AND PROPERTIES OF ELECTRODEPOSITED INDIUM TIN OXIDE/SNO2/CDTE AND INDIUM TIN OXIDE/SNO2/CDS/CDTE SOLAR-CELLS

Cadmium telluride-based solar cells have been prepared as indium tin oxide (ITO)/SnO2/CdTe and indium tin oxide/SnO2/CdS/CdTe structures where CdS and CdTe were prepared by an electrodeposition technique. Both open circuit voltage and short circuit current of ITO/SnO2/CdTe cells were higher than that of ITO/SnO2/CdS/CdTe cells. The spectral response measurement showed that the current collection was higher in the ITO/SnO2/CdTe cell relative to the ITO/SnO2/CdS/CdTe cell. Current-voltage temperature measurements indicated that the junction transport could be controlled by recombination or thermally assisted tunneling in the ITO/SnO2/CdTe cell, whereas tunneling could be the dominant junction transport mechanism in the ITO/SnO2/CdS/CdTe cell. Activation energies of ITO/SnO2/CdTe and ITO/SnO2/CdS/CdTe cells were 0.60 and 0.76 eV, respectively. The values of the built-in potential, V(bi) calculated from the measurement of open circuit voltage with temperature were 1.41 and 1.5 eV for ITO/SnO2/CdTe and ITO/SnO2/CdS/CdTe cells, respectively, whereas from Mott-Schottky plots they were 1.1 and 0.95 eV, respectively.