ZnO nanowire radial CdTe solar cells

CdTe solar cells which incorporate ZnO nanowires to form radial junctions are demonstrated. Complete cell structures were produced using ZnO nanowires deposited by electrodeposition of ~970nm in length. SEM analysis showed radial junction regions were formed within the cells, while optical analysis showed a reduction in the front surface reflection. Device efficiencies of up to 3.49% was achieved for these devices, with performance primarily limited by their low open circuit voltage and fill factor in comparison to standard cells. EQE analysis suggests that performance loss occurred as a result of increased intermixing between the CdTe and CdS layers. This contributed to the cell´s low shunt resistance and may have led to the formation of TCO/CdTe shorts, i.e. weak diode regions which reduced the open circuit voltage.