Modification of emission properties of ZnO layers due to plasmonic near-field coupling to Ag nanoislands

TL;DR

This study demonstrates how Ag nanoislands can enhance and modify the emission properties of ZnO layers through plasmonic near-field coupling, with effects depending on nanoisland size.

Contribution

It introduces a simple fabrication method for Ag nanoislands on ZnO and analyzes their impact on optical emissions using experimental and theoretical approaches.

Findings

Ag nanoislands cause a threefold increase in emission intensity.

Nanoisland size significantly influences plasmonic effects.

Recombination times are reduced by up to 1.5 times.

Abstract

A simple fabrication method of Ag nanoislands on ZnO films is presented. Continuous wave and time-resolved photoluminescence and transmission are employed to investigate modifications of visible and UV emissions of ZnO brought about by coupling to localized surface plasmons residing on Ag nanoislands. The size of the nanoislands, determining their absorption and scattering efficiencies, is found to be an important factor governing plasmonic modification of optical response of ZnO films. The presence of the Ag nanoislands of appropriate dimensions causes a strong (threefold) increase in emission intensity and up to 1.5 times faster recombination. The experimental results are successfully described by model calculations within the Mie theory.