Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 24 for “"valence band edge"”.
-
Surface states on the cleaved (III) silicon surface
… is related to the difference between the valence band edge and the Fermi level in the bulk and at the surface, and to the quantity of charge in the surface states which has been trapped from the bulk. Analysis of the data shows a high density of surface states on the clean cleaved surface, …
-
Photoemission Studies of the Electronic Structure and Properties of Thin Lead Films
… on whether they are above or below the Si valence band edge. They show large oscillations in the thermal stability. Adding 1 ML to a film can make it stable to an additional 50°C. The effective masses of the subbands also show some unusual features.
-
The electronic transport properties of undoped and doped arsenic triselenide
… (0.62eV) and E<sub>3</sub> (0.42eV) above the valence band edge.<br/><br/>Variation of the dispersion parameter with temperature in vitreous material supports the presence of structure at E<sub>2</sub> in the distribution of localised states N(E). Deviations from power law behaviour in the …
-
Probing technique for energy distribution of positive charges in gate dielectrics and its application to lifetime prediction
… it is essential to have an in-depth knowledge on the defects responsible for the recovery. It has been generally accepted that the NBTI recovery is dominated by the discharge of trapped holes. For the thin dielectric (e.g. < 3 nm) used by current industry, all hole traps are within direct …
-
Iron-oxide catalyzed silicon photoanode for water splitting
… of silicon to water splitting are its high valence band edge and the lack of catalytic functionality. The solution for band edge mismatch is to facilitate the unique pH response of silicon with respect to electrolyte pH. As opposed to the low pH, a high pH electrolyte allows the silicon …
-
High Pressure Effects on the Band Structure and Dye-Sensitized Photospectra of Semiconductors
… effect of high pressure (to 10 kilobars) on the band edge structure of n-TiO(,2), n-CdS, and n-CdSe has been investigated using an electrochemical technique. This study presents a novel method of measuring the energy of the band positions. It was found that the 3 meV/kbar increase in the band-gap …
-
Theoretical study on the band structure of Bi1̳-x̳Sbx̳ thin films
The study on the electronic band structures of Bi1-xSbx thin films is a very interesting topic. Recall that in bulk Bi1-xSbx, the electronic band structure can be varied as a function of temperature T, pressure P and stoichiometry. The electronic band structure does not change with T significantly …
-
Design, fabrication, and characterization of germanium MOSFETs with high-k gate dielectric stacks based on the nitride interfacial layers
… distribution of interface states in the bandgap is the primary cause of low electron mobility for germanium-A1N interfaces. The interface state density near the conduction band edge approaches 6x1013 cm-2 eVl, approximately 5x higher than near the valence band edge.
-
A tight-binding analysis of the electronic properties of III-nitride semiconductors
… alloys and InGaN quantum wells. We calculate the band gap evolution of Al1_xGaxN across the full composition range and compare it to experiment as well as fitting bowing parameters to the band gap as well as to the conduction band and valence band edges. We also investigate the wavefunction …
-
THE MODIFICATION OF ELECTROCHEMICAL AND PHOTOELECTROCHEMICAL PROPERTIES IN THIN FILMS OF TRI- AND TETRAVALENT METAL PHTHALOCYANINES
… Fermi level to move down in energy toward its valence band edge. Dosing the film with hydrogen caused the electrode to exhibit its original intrinsic characteristics. This variability in electrical properties as a function of gas dopant may lead to the development of a sensitive gas sensing …
-
Recombination lifetimes in gamma-irradiated silicon
… energy levels, one 0.17 ev from the conduction band edge, which was assumed to be the substitutional oxygen (A center) defect, and the other at 0.4 ev from the conduction band edge. On the basis of annealing data, it appeared that the 0.4 ev level could be due to several defects whose energy …
-
Ab Initio Study of Amorphous Zeolitic Imidazolate Framework (A-ZIF) and Pyrophosphate crystals
… phosphates show the presence of narrow metallic bands near the valence band edge. All these complex bonding affects their physical properties indicating that the fundamental understanding remains an open question.
-
Computational modeling of transport and growth-related processes of novel gallium-v materials for temperature-resilient and high-power electronics
… a small percentage of Bi results in significant band-gap reduction compared to that in pure GaAs, owing to the appearance of an impurity level just below the valence band edge. As a consequence, hole mobility is experimentally reported to drop. We carry out first-principles electronic structure …
-
InGaAs/GaAsSb quantum-well Tunnel-FETs for ultra-low power applications
… reported non-abruptness of the conduction/valence band-edge into the bandgap. The result indicates the possibility of achieving SS as low as 38 mV/dec in QWTFETs by improving gate efficiency by up to 78% with proposed optimized parameters based on simulation results. Non-logic TFET-specific …
-
Sulfur Implanted GaSb for Non-Epitaxial Photovoltaic Devices
Gallium antimonide (GaSb) is a promising low-bandgap binary substrate for the fabrication of various infrared-based optoelectronic devices, particularly thermophotovoltaics (TPV). In order to make GaSb-based technologies like TPV more widely available, non-epitaxial dop- ing methods for GaSb must …
-
Exploiting polar interfaces for photocatalytic water splitting: application to the anatase-cuprous oxide heterojunction
… been realized in experiment. Due to its low valence band edge, anatase has a good oxidation potential; by contrast cuprous oxide has a good reduction potential due to its high conduction band edge. This makes the heterosystem an intriguing candidate for photocatalytic water splitting; …
-
Electronic and optical properties of InAs nanocrystals
… spherical InAs nanocrystals. Our calculated interband (valence-to- conduction) absorption spectra reproduce the features observed experimentally both qualitatively and quantitatively. The results relative to intraband (valence-to-valence and conduction-to-conduction) absorption successfully …
-
Interface Trap Characterization of ALD-grown Al<sub>2</sub>O<sub>3</sub>/GaN MIS Capacitors
… to probe the interface over the entire GaN bandgap. To investigate the role of Al<sub>2</sub>O<sub>3</sub> thickness on interface state densities and explore the presence of Al<sub>2</sub>O<sub>3</sub> bulk traps, 6.8, 13.4, and 19.8nm thick films of ALD Al<sub>2</sub>O<sub>3</sub> were …
-
Growth and characterization of epitaxial silver indium diselenide
… step dynamics, leading to less faceted, straight edged island shapes compared to CIGS. Epitaxial temperature as a function of growth direction shows a different trend in AIS than in CIGS. Interdiffusion of the group III elements across the substrate interface was found to result in an epitaxial …
-
Plasmon supported defect absorption in amorphous silicon thin film solar cells and devices
… signal is observed for photon energies below the bandgap of a-Si:H. States must be present that allow transitions for sub-bandgap energies. By a variation of the Ag NP position within the applied devices the role of interface states is evaluated. It turns out that defects in the a-Si:H material …
Page 1 of 2