Alexandria Digital Research Library

Stress-Relaxation in III-Nitride Based Semipolar Lasers

Author:
Hsu, Po Shan
Degree Grantor:
University of California, Santa Barbara. Materials
Degree Supervisor:
Shuji Nakamura
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2013
Issued Date:
2013
Topics:
Engineering, General and Engineering, Materials Science
Genres:
Dissertations, Academic and Online resources
Dissertation:
Ph.D.--University of California, Santa Barbara, 2013
Description:

Semipolar growth orientations of wurtzite III-nitrides have fundamental advantages over the polar c-plane growth orientation for fabrication of visible long wavelength light emitting devices, e.g. light emitting diodes (LEDs) and laser diodes (LDs), due to a reduction of polarization-related electric fields in the quantum-wells (QWs). This results in devices with higher radiative recombination rates and reduced blueshift in the electroluminescence wavelength with increasing carrier injection. Growth of semipolar heterostructures, however, will often result in dislocation slip on the inclined (0001) basal plane and the formation of misfit dislocations (MDs) at highly mismatched heterointerfaces. Dislocations have been shown to act as nonradiative carrier sinks in GaN and its alloys and can therefore be extremely detrimental to optoelectronic device performance if located in proximity to the active region. As a result, optical waveguide design for defect-free semipolar AlInGaN LDs structures is greatly constrained within the limits for MD formation. We propose a two pronged approach in the III-nitride LD epitaxial growth: Growth of coherently strained LD structure on highly inclined semipolar {30 31} growth orientation with high critical thickness for stress relaxation. Growth of intentionally stress relaxed LD structure on lowly inclined semipolar (1122) growth orientation with low critical thickness for stress relaxation.

Physical Description:
1 online resource (170 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f3tb151k
ISBN:
9781303538933
Catalog System Number:
990040924610203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Po Shan Hsu
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