Performance and lifetime improvement of polymer/fullerene blend photovoltaic cells with a C60 interlayer

Polymer solar cell based on the blend of poly[2-methoxy-5-(2′-ethylhexoxy)-1,4-phenylene vinylene] (MEH-PPV) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) with C60 insertion layer were fabricated. The solar cell structure was ITO/poly(3,4-ethylenedioxythiopene) (PEDOT):poly(styrenesulfonate) (PSS)/MEH-PPV:PCBM/C60/Al. It was found that the C60 inserting layer could increase the device performance and lifetime. The energy conversion efficiency (ECE) of the solar cell with C60 layer reached about 1.89% under Air Mass 1.5, 100 mW cm−2 illumination, which is enhanced in comparison with that of the device without C60 layer. Mechanisms of the solar cell performance and lifetime dependence on the C60 layer are discussed.