Efficient Hybrid Infrared Solar Cells Based on P3HT and PbSe Nanocrystal Quantum Dots

The effects of composition on the performance of hybrid photovoltaic cells based on PbSe nanocrystal quantum dot(NQD)/ poly(3-hexylthiophene) nanocomposites were studied. The device performance and the absorption property strongly depended on the loading of PbSe. To improve the device performance, a pure light-absorbing P3HT film was inserted underneath the blended layer of P3HT and PbSe nanocrystal quantum dots in the active region. Such a design allowed for the employment of a thinner bulk heterojunction for more efficient carrier collection without an excessive reduction of the overall light absorption by the photovoltaic cell. The measured device performance showed a significant improvement over previously reported hybrid cells containing bulk heterojunctions of P3HT and Pb(S,Se) nanocrystal quantum dots.