Date of Award

3-9-2009

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Yung Kee Yeo, PhD

Abstract

Bulk grown III-V ternary semiconductors of In0.08Ga0.92Sb and In0.15Ga0.85As were investigated through Hall-effect and photoluminescence measurements to determine carrier concentration, mobility, sheet resistivity, and luminescence spectrum. In the past, epitaxial layers of ternary compounds have been grown on binary compound substrates, and thus very limited lattice matched ternary alloys were available. Recently, bulk grown ternary substrates have been developed, and it has presented a renewed interest in using these substrates to grow high quality ternary compounds for use in many next generation optoelectronic devices. The results of photoluminescence (PL) study for the In0.15Ga0.85Sb sample show the exciton bound to neutral acceptor (Ao,X) transition peak at 0.675 eV along with a donor-shallow acceptor pair transitions at 0.650 eV, and the donor-deep acceptor pair transition peak at 0.628 eV. The Hall-effect measurements show that this sample is an n-type material with carrier concentration of 4x1017/cm3 and mobility of 300 cm2/Vs at room temperature. The In0.80Ga0.20As sample is also an n-type material with a carrier concentration of 1.341x1016/cm3 and a mobility of 9,670 cm2/Vs at room temperature. The PL results of this sample shows a broad band to band peak at 0.572 eV. The PL taken at different positions of the sample show different band to band peak positions for the In0.80Ga0.20As sample, indicating a slight inhomogeneity in Ga concentration, while the PL observed from the In0.15Ga0.85Sb sample show position independent. Although the current bulk grown ternary alloy materials may not be as great yet as we hope for a direct use in next generation optoelectronic devices, it will provide suitable substrates for which to grow epitaxial layers.

AFIT Designator

AFIT-GMS-ENP-09-M01

DTIC Accession Number

ADA495843

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