Nanoscale optoelectronic properties of organic p–n junction P3HT/PCBM nanoparticles hybridized with CdSe/ZnS quantum dots

• Synthesis of organic p–n heterojunction P3HT/PCBM NPs hybridized with green-emitting CdSe/ZnS QDs.
• PL quenching of P3HT and PCBM with increasing QD concentration.
• Enhanced photocurrent of the hybrid P3HT/PCBM/QD single NP with increasing QD concentration.
• The results were analyzed in terms of effective charge dissociation and transfer behaviors.

Organic p–n junction nanoparticles (NPs) of p-type poly(3-hexylthiophene) (P3HT) and n-type [6,6]-phenyl C61-butyric acid methyl ester (PCBM) with approximate diameters of 80–250 nm were fabricated by a mini-emulsion method. Various concentrations of functionalized CdSe/ZnS quantum dots (QDs) were hybridized with P3HT/PCBM NPs. The photoluminescence (PL) spectra of the QDs mostly overlapped the absorption spectra of the P3HT/PCBM NPs, suggesting the activation of energy and/or charge-transfer effects. Using a high-resolution laser confocal microscope (LCM), we observed that the LCM PL intensity of a single P3HT/PCBM NP quenched with increasing QD concentration. Conducting atomic force microscopy revealed that the photocurrent of the P3HT/PCBM NP was enhanced as the QD concentration increased. After the hybridization of the P3HT/PCBM NPs with the QDs, the energy/charge-transfer effects and the charge dissociation of excitons with incident light have been more active, resulting in the increased photocurrent.

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