Amorphous and crystalline silicon nanocomposites have been shown to act as effective “sensitizers” for erbium ions. In the present work, a series of erbium-doped (0.2 at.%) SiOx:Er films (x ＝ 1 — 1:8) were synthesized by physical vapor deposition and subsequently annealed at temperatures ranging from 400°；C to 1100°；C to induce phase separation and cluster …
Tag Archive: CondensedMatter
Mar
09
Energy transfer and relaxation dynamics of europium-doped gallium nitride
This thesis describes a study of energy transfer mechanisms and relaxation dynamics of EuropiumEu)-doped GaN. Eu-doped GaN has been recently highlighted for its bright red visible electroluminescence and excellent spectral features. Doping with other rare earth elements, such as Erbium and Thulium, into a Nitride-based wide bandgap semiconductor allows fabrication of Red-Green-Blue full color display …
Mar
02
Simulation of two-phase dynamics using lattice Boltzmann method (LBM)
In this dissertation, a new lattice Boltzmann model, called the artificial interface lattice Boltzmann model AILB model), is proposed for the simulation of two-phase dynamics. The model is based on the principle of free energy minimization and invokes the Gibbs-Duhem equation in the formulation of non-ideal forcing function. Bulk regions of the two phases are …
Feb
18
The vapor phase condensation of metals in a gas evaporation condensation chamber
The vapor phase condensation of four metals was studied experimentally using a gas evaporation condensation chamber. Series of experiments were performed at constant total pressure. The roles of diffusion and nucleation in the chamber were investigated and a model employed to account for the effect they have on the experiment. Onset supersaturations of lithium, sodium, …
Feb
14
Gold nanorods: Synthesis, structural manipulation, and self-assembly
This work describes methods for the synthesis, structural manipulation, and self-assembly of one-dimensional gold nanostructures. The thesis begins with an efficient technique for the synthesis and separation of gold nanorods from a complex mixture, which has been a long standing challenge in the field of inorganic nanocrystals. The key aspect of our approach is the …
Feb
13
Chemical bath deposition of semiconductor thin films & nanostructures in novel microreactors
Chemical bath deposition CBD) offers a simple and inexpensive route to deposit semiconductor nanostructures and thin films, but lack of fundamental understanding and control of the underlying chemistry has limited its versatility. CBD is traditionally performed in a batch reactor, requiring only a substrate to be immersed in a supersaturated solution of aqueous precursors such …
Feb
11
Transport properties of epitaxial graphene films for nano-electronics applications
Graphene has been an excellent material for future nano electronics applications and has the potential to replace silicon due to its remarkable transport properties. Large-area epitaxial graphene film growth by thermal decomposition of SiC wafer has provided the missing pathway to a viable electronics technology. Epitaxial graphene film growth conditions and surface properties have been …
Jan
20
Anatase titanium dioxide thin film based carbon monoxide gas sensor
Gas sensors are finding increasing number of applications in home, industrial and automotive areas. Incomplete combustion in gas and coal fired electricity plants can generate harmful gases and pollutants. The purpose of the proposed research was to develop titanium dioxide TiO2) thin film based materials for carbon monoxide CO) gas sensing to detect a very …
Jan
20
Semiconductive behavior of and the fabrication of ap-n junction diode from amorphous polymer-derived ceramics
The electrical properties of high temperature semiconducting silicon oxycarbonitride (SiCNO) using titanium nitride (TiN) interconnects are studied. This research had three objectives. The first was to fabricate possible high temperature electrical ceramic and to construct metallic interconnects on SiCNO. The interconnect was selected by investigating the reaction between metals and SiCNO in powders by x-ray …
Jan
19
Development and fabrication of gallium nitride-based microdisk lasers using photoelectrochemical etching
The III-nitrides are very chemically stable materials. Because GaN and its alloys are extremely chemically resistant materials, the fabrication of microdisk lasers in the material system was challenging. Significant processing development was necessary. High quality GaN-based microdisk lasers were fabricated using bandgap-selective photoelectrochemical PEC) etching锛?a photo-induced etching technique which uses above bandgap illumination to generate …