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Full-Text Articles in Engineering
In Situ Electron Microscopy Of Plasmon-Mediated Nanocrystal Synthesis, Peter Sutter, Ying Li, Christos Argyropoulos, Eli A. Sutter
In Situ Electron Microscopy Of Plasmon-Mediated Nanocrystal Synthesis, Peter Sutter, Ying Li, Christos Argyropoulos, Eli A. Sutter
Department of Electrical and Computer Engineering: Faculty Publications
Chemical processes driven by nonthermal energy (e.g., visible light) are attractive for future approaches to energy conversion, synthesis, photocatalysis, and so forth. The growth of anisotropic metal nanostructures mediated by excitation of a localized surface plasmon resonance (LSPR) is a prototype example of such a reaction. Important aspects, notably the growth mechanism and a possible role of plasmonic “hot spots” within the metal nanostructures, remain poorly understood. Here, we use in situ electron microscopy to stimulate and image the plasmon-mediated growth of triangular Ag nanoprisms in solution. The quantification of the time-dependent evolution of the lateral size and thickness of …
Band-To-Band Transitions, Selection Rules, Effective Mass, And Excitonic Contributions In Monoclinic Β-Ga2o3, Alyssa Mock, Rafal Korlacki, Chad Briley, Vanya Darakchieva, Bo Monemar, Yoshinao Kumagai, Ken Goto, Masataka Higashiwaki, Mathias Schubert
Band-To-Band Transitions, Selection Rules, Effective Mass, And Excitonic Contributions In Monoclinic Β-Ga2o3, Alyssa Mock, Rafal Korlacki, Chad Briley, Vanya Darakchieva, Bo Monemar, Yoshinao Kumagai, Ken Goto, Masataka Higashiwaki, Mathias Schubert
Department of Electrical and Computer Engineering: Faculty Publications
We employ an eigenpolarization model including the description of direction dependent excitonic effects for rendering critical point structures within the dielectric function tensor of monoclinic β-Ga2O3 yielding a comprehensive analysis of generalized ellipsometry data obtained from 0.75–9 eV. The eigenpolarization model permits complete description of the dielectric response. We obtain, for single-electron and excitonic band-to-band transitions, anisotropic critical point model parameters including their polarization vectors within the monoclinic lattice. We compare our experimental analysis with results from density functional theory calculations performed using the Gaussian-attenuation-Perdew-Burke-Ernzerhof hybrid density functional. We present and discuss the order of the …
Anisotropy, Phonon Modes, And Lattice Anharmonicity From Dielectric Function Tensor Analysis Of Monoclinic Cadmium Tungstate, Alyssa Mock, Rafal Korlacki, Sean Knight, Mathias Schubert
Anisotropy, Phonon Modes, And Lattice Anharmonicity From Dielectric Function Tensor Analysis Of Monoclinic Cadmium Tungstate, Alyssa Mock, Rafal Korlacki, Sean Knight, Mathias Schubert
Department of Electrical and Computer Engineering: Faculty Publications
We determine the frequency dependence of four independent Cartesian tensor elements of the dielectric function for CdWO4 using generalized spectroscopic ellipsometry within mid-infrared and far-infrared spectral regions. Different single crystal cuts, (010) and (001), are investigated. From the spectral dependencies of the dielectric function tensor and its inverse we determine all long-wavelength active transverse and longitudinal optic phonon modes with Au and Bu symmetry as well as their eigenvectors within the monoclinic lattice. We thereby demonstrate that such information can be obtained completely without physical model line-shape analysis in materials with monoclinic symmetry. We then augment the …