Impact of Concentration Variations in P3HT: PCBM on Power Conversion Efficiency of Inverted Organic Solar Cell

In this paper, the solution dependent study on polymer: fullerene based bulk hetero-junction (BHJ) inverted organic solar cell (OSC) has been presented. It has been found that, in fabricated inverted OSC the power conversion efficiency (PCE) is strongly influenced by the weight ratio of donor and acceptor materials. Experimental results show that by modifying the weight ratio of poly (3-hexylthiophene) and phenyl C61 butyric acid methyl ester (P3HT: PCBM) in BHJ solution from 1.0:1.0 to 1.0:0.8, the PCE has been improved by ~40%. It has also been observed that, changes in blending ratio substantially increases the fill factor, open circuit voltage, and the short circuit current density of the device. Furthermore, with a weight ratio of 1.0:0.8, external quantum efficiency and the absorption spectrum also improves.