Abstract
The visible extinction of noble metal nanoparticles surpasses those of semiconductor and molecular dyes by several orders of magnitude. Such superior light-harvesting characteristics are highly attractive for photocatalytic applications. Of a particular interest is the process of the plasmon near-field energy conversion, which is predicted to yield substantial gains in the photocarrier generation. Here, we employ the sample-transmitted excitation photoluminescence (STEP) spectroscopy to determine the quantum efficiency for the plasmon induced resonant energy transfer (ET) in assemblies of Au nanoparticles and semiconductor quantum dots (CdSe, PbS, etc.). The present technique distinguishes the Au-to-QD ET contribution from metal-induced quenching processes thus enabling accurate estimates of the photon-to-exciton conversion efficiency. We show that in the case of 9.1-nm Au nanoparticles, only 1-2% of the Au absorbed radiation is converted to excitons in the surrounding CdSe nanocrystal matrix. For larger, 21.0-nm Au, the photon-to-exciton conversion efficiency increases to 29.5%. The results of present measurements were used to develop an empirical model for estimating the maximum gain in the plasmon-induced carrier generation versus the mass-fraction of Au.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.