Selective photoelectrochemical deposition of polypyrrole onto hydrogenated a-Si for optoelectronic applications

In this study a number of hybrid (polypyrrole (PPy)/i-a-Si:H/n-a-Si:H/AZO/glass) solar cells have been prepared and characterized. Hydrogenated amorphous silicon n-doped (n-a-Si:H) and intrinsic (i-a-Si:H) layers acted as a charge separation and photoabsorber layers, respectively. Doped PPy was electrodeposited onto the i-a-Si:H/n-a-Si:H/AZO/glass electrodes using the selective photo-assisted technique under various illumination. Electrodeposition was held at room temperature in an aqueous solution containing PPy and 1-naphthalene sulfonate or polystyrene sulfonate doping agents at low potential values ranging from 300 mV to 500 mV vs. saturated calomel electrode. The efficiency of the photo-assisted ED technique for producing of conductive uniform PPy layers onto the i-a-Si:H photoabsorber is confirmed. The overall photoconversion efficiency of the hybrid solar cells was about 2.9% and comparable for different PPy doping agents and illumination conditions of the ED process.