Role of Auger Recombination in Plasmon Controlled Photoluminescence Kinetics in Metal-Semiconductor Hybrid Nanostructures

TL;DR

This study demonstrates that integrating metal nanoparticles with semiconductor quantum dots can control photoluminescence decay dynamics, reducing non-radiative Auger recombination and enhancing light-emitting device efficiency.

Contribution

It reveals how plasmonic metal nanoparticles can be used to modulate exciton recombination pathways in quantum dots, a novel approach for optimizing hybrid nanostructures.

Findings

Hybridization reduces fast decay contributions when excited above bandgap.

Simultaneous excitation of exciton and plasmon reverses photoluminescence kinetics.

Control of decay times enables improved design of light-emitting devices.

Abstract

Spectroscopic studies of semiconductor quantum dots (SQDs) addressing the problem of non-radiative carrier losses is vital for the improvement in the efficiency of various light-emitting devices. Various designs of SQDs emitter like doping, forming core-shell and alloying has been attempted to suppress non-radiative recombination. In this article, we show that forming a hybrid with metal nanoparticles (MNP) having localized surface plasmon resonance overlapped with the emission spectrum of SQD, the non-radiative carrier loss via Auger recombination can be mitigated. Using steady-state and time-resolved photoluminescence, it has been shown that when such hybrid is selectively excited well above the bandgap without exciting plasmon, the contribution to fast decay time reduces along with an increase in contributions to longer decay times. A completely reverse kinetics is observed when exciton and plasmon are simultaneously excited. Such control of photoluminescence kinetics by placing MNP near SQD opens up a new method for designing hybrid materials that are well suited for light-emitting devices.