Augmented Photoluminescence in a Conjugated Polymer by the Incorporation of CdSe/CdS Quantum Dots

We investigated the photophysical interactions between CdSe/CdS quantum dots (QDs) and a conjugated polymer (CP, P3HT). The photoluminescence intensity of P3HT in the QDs/P3HT hybrid system is significantly enhanced compared to that of the neat P3HT system. We found via transient absorption spectroscopy that the energy level differences at the interfaces between P3HT and QDs resulted in delayed relaxation dynamics of the P3HT singlet (S1) excitons and suppressed polaron formation. Thus, the radiative recombination of the S1excitons occurs frequently in the hybrid system than in the neat P3HT system. Our findings on the CP-based hybrid system may provide important information to improve the efficiencies of optoelectronic devices, such as organic light-emitting diodes.