Retention of power conversion efficiency--from small area to large area polymer solar cells.

A light harvesting device geometry is implemented for polymer solar cells that retain efficiency when the device area is scaled up. Patterning devices and incorporating suitable fluorescent dye doped polymers in the spaces between the patterns leads to 12% efficiency enhancement. Vacuum free deposition of electrodes is carried out using meltable alloys giving rise to device efficiency of 6%. The fluorescent layer along with the electrode serves as an active encapsulant leading to improved device stability.