Efficient bulk heterojunction photovoltaic devices based on modified PCBM

Abstract

Organic bulk heterojunction solar cells are a promising candidate for low-cost next-generation photovoltaic systems. In bulk heterojunction polymer solar cells, conjugated polymers and fullerene derivatives [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) function as the electron-donating and electron-accepting materials, respectively. In this paper, we report the photovoltaic response of the solution-processed bulk heterojunction (BHJ) solar cell based on poly (2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV): modified PCBM (MPCBM) blend. The BHJ showed power conversion efficiency (PCE) up to 1.78%. The PCE has been further improved up to 1.95% after thermal annealing of the active layer. The increase in the PCE with the thermally annealed blend is mainly attributed to the improvement in incident photon to current efficiency (IPCE) and short circuit photocurrent (Jsc).