Daniel Wolverson

Raman Spectra of Monolayer, Few-Layer, and Bulk ReSe2: An Anisotropic Layered Semiconductor

Rhenium diselenide (ReSe2) is a layered indirect gap semiconductor for which micromechanical cleavage can produce monolayers consisting of a plane of rhenium atoms with selenium atoms above and below. ReSe2 is unusual among the transition-metal dichalcogenides in having a low symmetry; it is triclinic, with four formula units per unit cell, and has the bulk space group P1̅. Experimental studies of Raman scattering in monolayer, few-layer, and bulk ReSe2 show a rich spectrum consisting of up to 16 of the 18 expected lines with good signal strength, pronounced in-plane anisotropy of the intensities, and no evidence of degradation of the sample during typical measurements. No changes in the frequencies of the Raman bands with layer thickness down to one monolayer are observed, but significant changes in relative intensity of the bands allow the determination of crystal orientation and of monolayer regions. Supporting theory includes calculations of the electronic band structure and Brillouin zone center phonon modes of bulk and monolayer ReSe2 as well as the Raman tensors determining the scattering intensity of each mode. It is found that, as for other transition-metal dichalcogenides, Raman scattering provides a powerful diagnostic tool for studying layer thickness and also layer orientation in few-layer ReSe2.

Binding energy of charged excitons in ZnSe-based quantum wells

Excitons and charged excitons (trions) are investigated in ZnSe-based quantum well structures with (Zn,Be,Mg)Se and (Zn,Mg)(S,Se) barriers by means of magneto-optical spectroscopy. Binding energies of negatively

Superconductivity in two-dimensional NbSe2 field effect transistors

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Nanoimprint Lithography of Al Nanovoids for Deep-UV SERS

and positively

Optical investigation of degradation mechanisms in AlGaN/GaN high electron mobility transistors: Generation of non-radiative recombination centers

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Carbon nanoparticle surface functionalisation: converting negatively charged sulfonate to positively charged sulfonamide.

charged excitons are measured as functions of quantum well width, and free carrier density and in external magnetic fields up to 47 T. The binding energy of

Hydrothermal conversion of one-photon-fluorescent poly-(4-vinylpyridine) into two-photon-fluorescent carbon nanodots

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Origin of the red luminescence in Mg-doped GaN

shows a strong increase from 1.4 to 8.9 meV with decreasing quantum well width from 190 to

Strain-induced phonon shifts in tungsten disulfide nanoplatelets and nanotubes

29 \AA{}.

A Raman spectroscopic study of uranyl minerals from Cornwall, UK

The binding energies of