Date of Graduation

5-2012

Document Type

Thesis

Degree Name

Master of Science in Microelectronics-Photonics (MS)

Degree Level

Graduate

Department

Microelectronics-Photonics

Advisor/Mentor

Salamo, Gregory J.

Committee Member

Naseem, Hameed A.

Second Committee Member

Ware, Morgan E.

Third Committee Member

Vickers, Kenneth G.

Keywords

Applied sciences; Growth dynamics; Indium nitride

Abstract

The need for energy conservation has heightened the search for new materials that can reduce energy consumption or produce energy by the means of photovoltaic cells. III-nitride alloys show promise for these applications due to their generally good transport properties and ability to withstand high power applications. Along with these, this family of semiconductor alloys has a direct bandgap energy range (0.7-6.2 eV) which spans the entire visible spectrum and encompasses a large portion of the available solar spectrum. Of the three root III-nitride semiconductors, AlN, GaN, and InN, InN has only recently become attainable epitaxially with qualities good enough to characterize and use in devices. Much, however, is yet to be answered regarding the processes of crystal formation of InN. This study investigates the processes by which InN nanostructures form in MBE growth. A phase diagram depicting the various growth modes was created by varying the In/N flux ratio and growth temperature. A transition from a 2D to a 3D growth mode can be realized by lowering both the flux ratio (changing to an N rich growth) and the growth temperature.

Structural characterization of MBE grown InN was performed using X-ray Diffraction and Atomic Force Microscopy. Changes in the surface morphology are discussed and shown to be affected most by the indium and nitrogen adatom diffusion length, mobility, and nucleation densities. Characterization of the optical response of InN films was performed using Fourier transform spectroscopy. Trends in the structural periodicity and optical response were found and are presented within.

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