Date of Award

3-2023

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Christina L. Dugan, PhD

Abstract

Germanium tin (GeSn) alloys are being studied as potential transition metal (Group IV) photoelectric semiconductors or optical detectors. GeSn alloys could be employed as an optically active material within a computer. Compared to current technologies, a direct band gap GeSn alloy can be engineered to operate with higher thermal stability and efficiency. The GeSn alloy studied was composed of Ge and Si substrates with various Sn percentages grown using remote plasma-enhanced chemical vapor deposition (RPECVD). Photoluminescence spectroscopy (PL) techniques were initially used to determine the GeSn properties, including the band gap. The Ge91.2Sn8.8 PL spectra suggested the band gap energies were below the detection threshold. In addition, samples containing lower Sn concentrations appeared to be non-radiative. Additional investigations using the Scanning Electron Microscope (SEM) provided indications of surface roughness and Sn surface migration within the GeSn samples. Using Electron Dispersive Spectroscopy (EDS) at multiple probing energy potentials confirmed variations in Sn concentrations throughout the sample.

AFIT Designator

AFIT-ENP-MS-23-M-107

Comments

A 12-month embargo was observed.

Cleared for public release. PA case number on file.

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