We report the investigation of composites of poly-(3-hexylthiophene) (P3HT) and CuInSe 2 nanocrystals (NCs). CuInSe 2 NCs were synthesized at gram scale through a colloidal route. Cyclic voltammetry was used to determine the HOMO-LUMO energy levels, as well as the energies of trap states intrinsic to CuInSe 2 NCs. The results suggest that nanocrystal-polymer charge transfer is foreseeable in the P3HT and CuInSe 2 system because of their type II band alignment. We studied optical properties of the hybrid composite films of P3HT and CuInSe 2 NCs as a function of P3HT/CuInSe 2 NCs weight ratios. The quenching of photoluminescence spectra with the increase of CuInSe 2 ratio in the composite was interpreted to result from charge transfer between the polymer and CuInSe 2 NCs. We further studied photodiode devices that exhibited a transition from photoconductive gain to the photovoltaic effect with an increase of the P3HT/CuInSe 2 weight ratio. Performance of the photovoltaic devices was strongly limited by intrinsic traps associated with the CuInSe 2 NCs.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films