Effect of Nanoscale Defects on Electrical and Optical Properties in Iii-V Semiconductors

The Schrodinger equation, in a real space k·p Hamiltonian formation, is solved using the finite element method to study effects of edge and screw dislocations on optical properties in GaN. Energy levels and corresponding wave functions are obtained for the conduction and valence bands, and spontaneous emission spectra are evaluated to compare with available experimental results. Inhomogeneous band edge shifts for each subband due to the strain fields associated with each type of dislocation, plus the electrostatic potential of edge dislocations, generate spatial separation between electrons and holes resulting in optical emission reduction. Both calculated and experimental data show emission intensity reduction as dislocation density increases. Dislocation effects in GaAs are then investigated and compared with GaN. It is shown that GaAs is more sensitive to dislocations due to a comparatively light effective mass and large deformation fields of the dislocations.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• You, Jeong Ho

Contributors dc:contributor

• Johnson, Harley T.

• Engineering, Materials Science

Language dc:language

eng

Identifier

(MiAaPQ)AAI3290447

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/83894