3-Hexylthiophene, CAS number 1693-86-3, is the intermediate for the synthesis of poly(3-hexylthiophene), referred as P3HT. To date, it is the most studied polymer for polymer solar cells. The efficiency of a P3HT/PCBM solar cell is typically 4-5 %, but with new fullerene materials developed to closely match the energy levels of P3HT (HOMO 5.0 eV, LUMO 3.0 eV), device performances have been pushed to 6.5% [1].
The synthesis of P3HT is relatively easy and short, only a 3-4 step synthesis is required [2, 3, 4]. The challenge of P3HT is that it only absorbs a narrow band of solar spectrum, so it has little room for improvement in terms of performance efficiency.