Thermal annealing effect of organic solar cells using organofullerene/solvent co-crystals

我们利用有机/溶剂共晶体研究了有机太阳能电池的热退火效应。在加热条件下，富勒烯共晶向无定形中间相转变，电子迁移率降低，高温晶化使其电子迁移率增大。然而，电子迁移率的变化与光伏性能并不相关。相反，当无定形中间相的迁移率最小时，性能最好。结果表明，施主和受主界面上的分子水平接触成为影响太阳能电池性能的关键因素。

We examined a thermal annealing effect of organic solar cells by using organo/solvent co-crystals. Electron mobility of the co-crystal of fullerene was decreased by the phase transition to amorphous mesophase under the heating, and it was then, increased by the thermal crystallization at the high temperature annealing. The changes of the electron mobility, however, did not correlated with the photovoltaic performance. Rather, performance was maximized when the mobility was minimized at the amorphous mesophase. The result suggesting that the molecular level contact at interface between the donor and acceptor become a crucial factor for the solar cells.