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Full-Text Articles in Physical Sciences and Mathematics
Investigation Of The Chemical And Electronic Structure Of A 2h Phase Mos2 Single Crystal, Mary Blankenship
Investigation Of The Chemical And Electronic Structure Of A 2h Phase Mos2 Single Crystal, Mary Blankenship
UNLV Theses, Dissertations, Professional Papers, and Capstones
Molybdenum disulfide has a wide range of applications in energy conversion devices, like thin-film solar cells, batteries, bio sensors, and more. Although the properties of MoS2 and other transition metal dichalcogenides (TMDC) have been widely studied, disagreements and discrepancies regarding its electronic structure remain. In this thesis, a highly-oriented synthetic 2H phase MoS2 single crystal is investigated using a toolchest of spectroscopic techniques to uncover its chemical and electronic properties. Lab-based x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), inverse photoemission spectroscopy (IPES), and low energy electron diffraction (LEED) were performed at UNLV and combined with resonant inelastic soft x-ray …
Synchrotron Study Of Phase Transition And Heterostructures In Metal Oxide Semiconductors, Bingyu Dong
Synchrotron Study Of Phase Transition And Heterostructures In Metal Oxide Semiconductors, Bingyu Dong
Electronic Thesis and Dissertation Repository
Transition metal oxides, including titanium dioxide (TiO2), zinc oxide (ZnO) and Tin dioxide (SnO2) are widely recognized semiconducting photocatalysts. This project engages in a detailed examination of the phase transition of TiO2 and the synthesis of heterostructured metal oxides using an eco-friendly method of ball-milling. A variety of spectroscopy and microscopy techniques have been used to analyze the products. Synchrotron-based techniques: X-ray Absorption near-edge spectroscopy (XANES), X-ray Emission Spectroscopy and X-ray excited optical luminescence (XEOL) can demonstrate the local structure and bonding. The finding highlights a phase transition in TiO2 and the formation of …
Isolating The Electronic Effects Of Systematic Twist In Highly Substituted Aromatic Hydrocarbons Using Density Functional Theory, Grace Tully, Emily A. Jarvis
Isolating The Electronic Effects Of Systematic Twist In Highly Substituted Aromatic Hydrocarbons Using Density Functional Theory, Grace Tully, Emily A. Jarvis
Honors Thesis
Density functional theory (DFT) was employed to investigate dodecaphenyltetracene as well as similar molecules containing differing backbone lengths and electron withdrawing groups with interest in manipulating the twist to lower the LUMO level for increased electron mobility. Optimization and frequency time-independent calculations followed by time-dependent (TD-DFT) energy calculations were performed at the B3LYP/G-311G level of theory to analyze electronic trends as a result of increased backbone length and consequently distorted end-to-end molecular twist. These calculations demonstrate a linear relationship with negative slope between the estimated HOMO-LUMO, fundamental, and optical gaps as a function of the number of fused rings along …
Development Of Nonorthogonal Wavefunction Theories And Application To Multistate Reaction Processes., Emily Kempfer
Development Of Nonorthogonal Wavefunction Theories And Application To Multistate Reaction Processes., Emily Kempfer
Electronic Theses and Dissertations
Many prominent areas of technological development rely on exploiting the photochemical response of molecules. An application of particular interest is the control of molecular switches through a combination of different external stimuli. However, despite significant advances in theoretical approaches and numerous cases of successful application of theory, simulating photochemical reactions remains a computational challenge. Theoretical methods for describing excited states can be broadly divided into single-reference response methods and multireference methods. Single reference methods provide reliable semiquantitative results for single excitations. However, these methods cannot describe double-excited states, systems with strongly correlated ground states, or regions of degeneracy on the …