Nanoscale Relative Emission Efficiency Mapping Using Cathodoluminescence g(2) Imaging

Sophie Meuret, Toon Coenen, Steffi Y. Woo, Yong Ho Ra, Zetian Mi, Albert Polman

Research output: Contribution to journalArticlepeer-review

37 Scopus citations

Abstract

Cathodoluminescence (CL) imaging spectroscopy provides two-dimensional optical excitation images of photonic nanostructures with a deep-subwavelength spatial resolution. So far, CL imaging was unable to provide a direct measurement of the excitation and emission probabilities of photonic nanostructures in a spatially resolved manner. Here, we demonstrate that by mapping the cathodoluminescence autocorrelation function g(2) together with the CL spectral distribution the excitation and emission rates can be disentangled at every excitation position. We use InGaN/GaN quantum wells in GaN nanowires with diameters in the range 200-500 nm as a model system to test our new g(2) mapping methodology and find characteristic differences in excitation and emission rates both between wires and within wires. Strong differences in the average CL intensity between the wires are the result of differences in the emission efficiencies. At the highest spatial resolution, intensity variations observed within wires are the result of excitation rates that vary with the nanoscale geometry of the structures. The fact that strong spatial variations observed in the CL intensity are not only uniquely linked to variations in emission efficiency but also linked to excitation efficiency has profound implications for the interpretation of the CL data for nanostructured geometries in general.

Original languageEnglish
Pages (from-to)2288-2293
Number of pages6
JournalNano Letters
Volume18
Issue number4
DOIs
StatePublished - Apr 11 2018
Externally publishedYes

Funding

This work is part of the research program of the “Nederlandse organisatie voor Wetenschappelijk Onderzoek” (NWO). It is also funded by the European Research Council (ERC). Y.H.R. and Z.M. thank the support from the Natural Sciences and Engineering Research Council of Canada (NSERC) and National Science Foundation (Grant ECCS-1709207). This work is part of the research program of the Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO). It is also funded by the European Research Council (ERC). Y.H.R. and Z.M. thank the support from the Natural Sciences and Engineering Research Council of Canada (NSERC) and National Science Foundation (Grant ECCS-1709207).

FundersFunder number
National Science Foundation1709207, 695343, ECCS-1709207
Natural Sciences and Engineering Research Council of Canada
European Research Council
National Science Foundation

    Fingerprint

    Dive into the research topics of 'Nanoscale Relative Emission Efficiency Mapping Using Cathodoluminescence g(2) Imaging'. Together they form a unique fingerprint.

    Cite this