Excitation wavelength-dependent photoluminescence decay of single quantum dots near plasmonic gold nanoparticles

Yonglei Sun; Yongchen Wang; Hua Zhu; Na Jin; Adnan Mohammad; Necmi Biyikli; Ou Chen; Kun Chen; Jing Zhao

doi:10.1063/5.0089090

Excitation wavelength-dependent photoluminescence decay of single quantum dots near plasmonic gold nanoparticles

J Chem Phys. 2022 Apr 21;156(15):154701. doi: 10.1063/5.0089090.

Authors

Yonglei Sun¹, Yongchen Wang², Hua Zhu³, Na Jin³, Adnan Mohammad⁴, Necmi Biyikli¹, Ou Chen³, Kun Chen⁵, Jing Zhao¹

Affiliations

¹ Institute of Materials Science, University of Connecticut, Storrs Mansfield, Connecticut 06269, USA.
² Department of Chemistry, University of Connecticut, Storrs Mansfield, Connecticut 06269, USA.
³ Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
⁴ Department of Electrical and Computer Engineering, University of Connecticut, Storrs Mansfield, Connecticut 06269, USA.
⁵ Department of Statistics, University of Connecticut, Storrs Mansfield, Connecticut 06269, USA.

PMID: 35459297
DOI: 10.1063/5.0089090

Abstract

Changing the excitation wavelength is a simple but effective strategy to modulate the photophysical cha racteristics of colloidal quantum dots (QDs) near plasmonic nanostructures. It has been observed that the photoluminescence (PL) decay of QDs near plasmonic nanostructures differs when the excitation wavelength is varied, but the exact mechanism is still unclear today. Here, we studied the excitation wavelength dependence of the PL decay of CdSe/CdS core/shell QDs near plasmonic gold nanoparticles at the single QD level. With the aid of statistical science, we demonstrated that the PL decay of a single QD near gold nanoparticles is generally faster when the QD is excited spectrally close to the localized surface plasmon resonance of gold nanoparticles. This excitation wavelength dependence is mainly caused by the varied proportion of photons coming from biexciton emission, which is the result of different local electric field enhancement by gold nanoparticles upon excitation.