Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Engineering

The Effects Of Pressure On Wide Bandgap Gan Semiconductors, William Kang, Linda Tran, Eunja Kim Aug 2009

The Effects Of Pressure On Wide Bandgap Gan Semiconductors, William Kang, Linda Tran, Eunja Kim

Undergraduate Research Opportunities Program (UROP)

Gallium nitride (GaN) is a group-III nitride semiconductor; which may prove useful in developing optical instruments that operate under high ambient pressures. The purpose of this project is to examine the properties of GaN under varying conditions. The methods used in this experiment consist of modeling free energy as a function of lattice constants; calculating bond lengths, bond strengths, and bulk moduli; and comparing the resultant data with values in published literature. We will also compare these results with experimental data drawn from x-ray diffraction scans. By doing so, we hope to determine whether gallium nitride is suitable for use …


Proton Irradiation Effects On Semiconductor Cdse/Zns Core/Shell Nanocrystals, Stephen Graham Charter Aug 2009

Proton Irradiation Effects On Semiconductor Cdse/Zns Core/Shell Nanocrystals, Stephen Graham Charter

Graduate Theses and Dissertations

The absorbance and photoluminescence measurement of semiconductor CdSe/ZnS core shell nanocrystals were reviewed and investigated after they were exposed to proton irradiation. The CdSe/ZnS core shell nanocrystals of 3.2nm and 4.4nm were commercially purchased and investigated. These nanocrystals were embedded in UV resin. Proton irradiation of energy 2MeV was applied at doses from 3 x 1013 protons cm-2 to 1.47 x 1015 protons cm-2 for both nanocrystal sizes. Absorbance measurements were conducted at 300K. Results from absorbance measurements showed slight broadening of the first exciton peak of both samples but was most noticeable in the 3.2nm nanocrystal sample. UV resin …


Growth And Characterization Of Chromium Doped Indium Oxide Diluted Magnetic Semiconductors, Ndubuisi Benjamin Ukah Jan 2009

Growth And Characterization Of Chromium Doped Indium Oxide Diluted Magnetic Semiconductors, Ndubuisi Benjamin Ukah

MSU Graduate Theses

Recently, enormous research efforts have been directed at diluted magnetic semiconductors (DMS) critical for realization for multi-functional spintronic devices. However, the origin of electronic and magnetic properties in DMS is not well understood. This study is aimed to better understand the structural, optical, magnetic, and magneto-transport property relationships of Cr-doped In2O3 (In2O3:Cr) DMS grown under different partial oxygen pressures on sapphire substrates using pulsed laser deposition technique. The thin films were characterized using various state-of-the-art techniques such as x-ray diffraction (XRD), UV-VIS spectroscopy, magnetotransport, and SQUID magnetometer. Expansions in lattice parameter (10.10 Å to 10.34 Å) and crystal size (13.9 …