Title:
Investigation of self-heating and macroscopic built-in polarization effects on the performance of III-V nitride devices

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dc.contributor.advisor Yoder, P. Douglas
dc.contributor.author Venkatachalam, Anusha en_US
dc.contributor.committeeMember Graham, Samuel
dc.contributor.committeeMember Allen, Janet
dc.contributor.committeeMember Klein, Benjamin
dc.contributor.committeeMember Voss, Paul
dc.contributor.department Electrical and Computer Engineering en_US
dc.date.accessioned 2009-08-26T17:44:22Z
dc.date.available 2009-08-26T17:44:22Z
dc.date.issued 2009-07-06 en_US
dc.description.abstract The effect of hot phonons and the influence of macroscopic polarization-induced built-in fields on the performance of III-V nitride devices are investigated. Self-heating due to hot phonons is analyzed in AlGaN/GaN high electron mobility transistors (HEMTs). Thermal transport by acoustic phonons in the diffusive limit is modeled using a two-dimensional lattice heat equation. The effect of macroscopic polarization charges on the operation of blue and green InGaN-based quantum well structures is presented. To characterize these structures, the electronic part of the two-dimensional quantum well laser simulator MINILASE is extended to include nitride bandstructure and material models. A six-band k.p theory for strained wurtzite materials is used to compute the valence subbands. Spontaneous and piezoelectric polarization charges at the interfaces are included in the calculations, and their effects on the device performance are described. Additionally, k.p Hamiltonian for crystal growth directions that minimize the polarization-induced built-in fields are modeled, and valence band dispersion for the non-polar and semi-polar planes are also calculated. Finally, a design parameter subspace is explored to suggest epitaxial layer structures which maximize gain spectral density at a target wavelength for green InxGa1-xN-based single quantum well active regions. The dependence of the fundamental optical transition energy on the thickness and composition of barriers and wells is discussed, and the sensitivity of gain spectral density to design parameters, including the choice of buffer layer material, is investigated. en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/29669
dc.publisher Georgia Institute of Technology en_US
dc.subject High electron mobility transistors en_US
dc.subject Nitrides en_US
dc.subject InGaN-based green lasers en_US
dc.subject Polarization en_US
dc.subject Self-heating en_US
dc.subject Quantum wells en_US
dc.subject.lcsh Transition metal nitrides
dc.subject.lcsh Semiconductors Materials
dc.subject.lcsh Phonons
dc.subject.lcsh Modulation-doped field-effect transistors
dc.subject.lcsh Semiconductor lasers
dc.subject.lcsh Quantum wells
dc.title Investigation of self-heating and macroscopic built-in polarization effects on the performance of III-V nitride devices en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Yoder, P. Douglas
local.contributor.corporatename School of Electrical and Computer Engineering
local.contributor.corporatename College of Engineering
relation.isAdvisorOfPublication 7d6cdbe1-1dc7-439d-ab9c-3823d6c2f6f9
relation.isOrgUnitOfPublication 5b7adef2-447c-4270-b9fc-846bd76f80f2
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
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