What is it about?
To collect the tiny light emission from a few atoms, a special light collector and an atomic resolution microscope are needed. Here, we used a special parabolic mirror that fits inside a scanning tunneling microscope. The ensemble is much more efficient than previous attempts, and it has shown its performance in some already published results. The details of the construction of this system are presented here.
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Why is it important?
This new device is important because it opens new ways to explore and understand properties of matter in the nanoscale. One can study luminescence and morphology with high spectral and spatial resolution.
Perspectives
This article represents the maturity of our research and that the development of our instrument is finally complete. Now we can dedicate our time to use this microscope to explore new materials and other researchers can follow along by building their instrument in a similar way.
Dr Luiz Fernando Zagonel
unicamp
Read the Original
This page is a summary of: Design and implementation of a device based on an off-axis parabolic mirror to perform luminescence experiments in a scanning tunneling microscope, Review of Scientific Instruments, April 2022, American Institute of Physics,
DOI: 10.1063/5.0078423.
You can read the full text:
Resources
Interplay Among Morphological, Optical and Electronic Properties in 2D Monolayers
Two-dimensional materials have attracted considerable attention due to the discovery of new and promising electronic and optical properties that could be used in flexible electronics, light emitting diodes and many other applications. 2D materials like transition metal dichalcogenides and h-BN become direct bandgap semiconductors when thinned to one monolayer and exhibit high exciton binding energy which turns them into good light emitters at room temperatures. These materials usually present defects like vacancies and inclusions that can lead to doping and single photon emissions among other effects. However, the intricate relation between morphology, electronic structure and luminescence is still missing in most cases. In this webinar, we will show that by collecting light emitted by 2D monolayers within a Scanning Tunnelling Microscope (STM), it is possible to determine the sample morphology (by imaging), sample electronic bandgap and band alignment (by tunnel current spectroscopy, STS), and sample luminescence spectra by collecting light emission triggered by electrons.[1] This webinar will further demonstrate that defects on tungsten diselenide cause p-type doping and that injecting electrons at the conduction band edge induces excitonic light emission.[2] Finally, we will illustrate the exciton biding energy of h-BN and intragap states related to observed defects in the same region where defect related luminescence was recorded. [3] We consider that other studies will largely benefit from this kind of facility and other problems linked to defect-related optical properties will be solved by the use of highly efficient light detection operating within an STM. The same strategy shared in this webcast can be used to better understand light emission from individual quantum dots or other nanoscale systems. [1] AIP Rev. Sci. Instrum. 93, 043704 (2022) [2] RSC Nanoscale 12, 13460 (2020) [3] IOP 2D Mater. 8, 044001 (2021)
arXiv:2210.04833 [pdf, other] physics.ins-det cond-mat.mtrl-sci doi 10.1063/5.0078423 Design and implementation of a device based on an off-axis parabolic mirror to perform luminescence experiments in a scanning tunneling microscope
Accepted Manuscript on ArXiv server.
List of articles using this device
This is a list of manuscripts of published articles by the corresponding author.
Contributors
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