Novel patterned layer to enhance conversion efficiency of amorphous silicon thin-film solar cells

The substrate of an a-Si:H solar cell with microscale surface roughness generally shows high diffuse transmittance; however, it also has detrimental effects, including low open-circuit voltage and fill factor (FF). We applied planarization to the rough surface using spin-coating of ZnO nanoparticles dispersed in an ethanol-based solution. The resulting conversion efficiency of the solar cell increased by 18% owing to the higher open-circuit voltage and FF, with a small decrease in the diffused transmittance