Hole transport and electrical properties in poly(p-phenylene vinylene): methanofullerene bulk-heterojunction solar cells

The dependence of the hole transport and electrical properties of OC1C10-PPV:PCBM (poly(2-methoxy-5-(3', 7'-dimethyloctyloxy)-p-phenylene vinylene): methanofullerene [6,6]-phenyl C-61-butyric acid methyl ester)-based bulk-heterojunction solar cells on their composition has been investigated. It is demonstrated that the current density versus voltage (J - V) characteristics of OC1C10-PPV:PCBM devices can be accurately described by using our recently introduced mobility model. Furthermore, we find that the width of the Gaussian density of states sigma and hole zero-field mobilities in blends of OC1C10-PPV: PCBM are a function of PCBM weight percentage. The hole mobilities sigma gradually increase with increasing fullerene concentration, whereas the values of the width of the Gaussian density of states. gradually decrease with increasing fullerene concentration. In addition, it is shown that the boundary carrier density of OC1C10-PPV:PCBM-based devices has an important effect on the J - V characteristics, and the variation of voltage with boundary carrier density is dependent on the current density.