STM-electroluminescence from clustered C 3 N 4 nanodomains synthesized via green chemistry process.

Authors :: Andrade EP
Costa BBA
Chaves CR
de Paula AM
Cury LA
Malachias A
Safar GAM
Source :: Ultrasonics sonochemistry [Ultrason Sonochem] 2018 Jan; Vol. 40 (Pt A), pp. 742-747. Date of Electronic Publication: 2017 Aug 23.
Publication Year :: 2018
Abstract: A Scanning Tunneling Microscopy/Spectroscopy (STM/STS) and synchrotron X-ray diffraction study on clustered C <subscript>3</subscript> N <subscript>4</subscript> nanoparticles (nanoflakes) is conducted on green-chemistry synthesized samples obtained from chitosan through high power sonication. Morphological aspects and the electronic characteristics are investigated. The observed bandgap of the nanoflakes reveals the presence of different phases in the material. Combining STM morphology, STS spectra and X-ray diffraction (XRD) results one finds that the most abundant phase is graphitic C <subscript>3</subscript> N <subscript>4</subscript> . A high density of defects is inferred from the XRD measurements. Additionally, STM-electroluminescence (STMEL) is detected in C <subscript>3</subscript> N <subscript>4</subscript> nanoflakes deposited on a gold substrate. The tunneling current creates photons that are three times more energetic than the tunneling electrons of the STM sample. We ponder about the two most probable models to explain the observed photon emission energy: either a nonlinear optical phenomenon or a localized state emission.<br /> (Copyright © 2017 Elsevier B.V. All rights reserved.)

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