Organic solar cells with a blend of two solution processable electron acceptors, C60(CN)2 and PCBM

Abstract

Organic solar cells based on bulk heterojunction (BHJ) structure fabricated by blending conjugated polymers with fullerenes have resulted in great improvements in the energy conversion efficiencies in recent years. PCBM ([6,6]-phenyl-C61-butyric acid methyl ester), a fullerene derivative, has been extensively investigated as a solution processable electron acceptor for BHJ photovoltaic devices blended with conjugate polymers like P3HT [poly(3-hexylthiophene)]. We investigated a novel solution processable organic semiconductor, C60(CN)2 as an electron acceptor and blends with PCBM for BJH photovoltaic applications . The effect of ratios of PCBM and C60(CN)2 on the optical absorption spectra, open circuit voltage, short circuit current, fill factor, efficiency and morphology is investigated. Thermal annealing has shown a significant improvement in the device performance.