Doping poly(3-hexylthiophene) nanowires with selenophene increases the performance of polymer-nanowire solar cells

Developing novel materials analogous to poly(3-hexylthiophene) (P3HT) with increased absorption range and good one-dimensional self-assembly properties should increase photovoltaic performance while taking advantage of the well-established structure-property relationships developed for P3HT. Herein, we have fabricated novel polymer nanowires composed of P3HT doped with varying amounts of selenophene. Doping is accomplished by statistical polymerization and results in the incorporation of selenophene into the P3HT crystal lattice. Selenophene doping increases optical absorption far beyond what can be achieved by simply blending two materials. Polymer nanowire solar cells using selenphene-doped P3HT outperform native P3HT nanowire and corresponding ternary blend solar cells, reaching an overall maximum performance of >4% PCE. These are some of the highest values of any polymer nanowire solar cells and show that the selenophene-doping strategy is important for achieving high-performance devices.