Spatially Resolved Raman Spectroscopy of Carbon Electrode Surfaces:  Observations of Structural and Chemical Heterogeneity

1997 ◽  
Vol 69 (22) ◽  
pp. 4680-4687 ◽  
Author(s):  
Kenneth Ray ◽  
Richard L. McCreery
1999 ◽  
Vol 607 ◽  
Author(s):  
A. Saher Helmy ◽  
A.C. Bryce ◽  
C.N. Ironside ◽  
J.S. Aitchison ◽  
J.H. Marsh ◽  
...  

AbstractIn this paper we shall discuss techniques for accurate, non-destructive, optical characterisation of structures fabricated using quantum well intermixing (QWI). Spatially resolved photoluminescence and Raman spectroscopy were used to characterise the lateral bandgap profiles produced by impurity free vacancy disordering (IFVD) technology. Different features were used to examine the spatial resolution of the intermixing process. Features include 1:1 gratings as well as isolated stripes. From the measurements, the spatial selectivity of IFVD could be identified, and was found to be ∼4.5 μm, in contrast with the spatial resolution of the process of sputtering induced intermixing, which was found to be ∼2.5 μm. In addition, PL measurements on 1:1 gratings fabricated using IFVD show almost complete suppression of intermixing dielectric cap gratings with periods less than 10 microns. Finally, some insight into the limitations and merits of PL and Raman for the precision characterisation of QWI will be presented.


2018 ◽  
Vol 38 (6) ◽  
pp. 1204-1207 ◽  
Author(s):  
Almagul Zhanaidarova ◽  
Andrew L. Ostericher ◽  
Christopher J. Miller ◽  
Simon C. Jones ◽  
Clifford P. Kubiak

Nanoscale ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 2398-2403 ◽  
Author(s):  
Haotian Shi ◽  
Nirakar Poudel ◽  
Bingya Hou ◽  
Lang Shen ◽  
Jihan Chen ◽  
...  

We report a novel approach to probe the local ion concentration at graphene/water interfaces using in situ Raman spectroscopy.


Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3325 ◽  
Author(s):  
Jovanny Gómez Castaño ◽  
Luc Boussekey ◽  
Jean Verwaerde ◽  
Myriam Moreau ◽  
Yeny Tobón

A new device and methodology for vertically coupling confocal Raman microscopy with optical tweezers for the in situ physico- and photochemical studies of individual microdroplets (Ø ≤ 10 µm) levitated in air is presented. The coupling expands the spectrum of studies performed with individual particles using laser tweezers Raman spectroscopy (LTRS) to photochemical processes and spatially resolved Raman microspectroscopy on airborne aerosols. This is the first study to demonstrate photochemical studies and Raman mapping on optically levitated droplets. By using this configuration, photochemical reactions in aerosols of atmospheric interest can be studied on a laboratory scale under realistic conditions of gas-phase composition and relative humidity. Likewise, the distribution of photoproducts within the drop can also be observed with this setup. The applicability of the coupling system was tested by studying the photochemical behavior of microdroplets (5 µm < Ø < 8 µm) containing an aqueous solution of sodium nitrate levitated in air and exposed to narrowed UV radiation (254 ± 25 nm). Photolysis of the levitated NaNO3 microdroplets presented photochemical kinetic differences in comparison with larger NaNO3 droplets (40 µm < Ø < 80 µm), previously photolyzed using acoustic traps, and heterogeneity in the distribution of the photoproducts within the drop.


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