Photoluminescence Enhancement in CdSe/CdS Quantum Dot Colloidal Films Induced by Gold Nanoparticles (AuNPs)

The optical properties of quantum dots (QDs) can be altered by employing surface plasmon metallic nanoparticles close to the QDs. In this study, we investigate the photoluminescence (PL) enhancement of CdSe/CdS core-shell QDs coupled with gold nanoparticles (AuNPs) due to the plasmonic effect. The effect of the morphology of AuNPs and the importance of the spacer layer were also analyzed. The AuNPs are deposited on a glass substrate by magnetron sputtering to achieve precise morphological control. The deposited nanoparticles have a uniform distribution and optimal particle size ranging between 10 and 12 nm. A poly-(methyl methacrylate) (PMMA) spacer layer was employed between QDs and AuNPs to control the separation and avoid quenching effects due to Förster resonance energy transfer (FRET). Maximum PL enhancement was observed for a spacer layer of 25 nm thickness due to the plasmonic effect. This coupled structure can potentially be used to enhance the PL of QDs acting as a downshifting layer, which can be used to improve the power conversion efficiency (PCE) and improve light trapping in solar cells.