Fabrication and Characterization of Micro-membrane GaN Light Emitting Diodes

Handle URI:
http://hdl.handle.net/10754/554110
Title:
Fabrication and Characterization of Micro-membrane GaN Light Emitting Diodes
Authors:
Liao, Hsien-Yu ( 0000-0002-6720-5831 )
Abstract:
Developing etching of GaN material system is the key to device fabrications. In this thesis, we report on the fabrication of high throughput lift-off of InGaN/GaN based micro-membrane light emitting diode (LED) from sapphire substrate using UV-assisted photoelectroless chemical (PEsC) etching. Unlike existing bandgap selective etching based on unconventional sacrificial layer, the current hydrofluoric acid based wet etching process enables the selective etching of undoped GaN layer already incorporated in standard commercial LED structures, thus attaining the leverage on high performance device design, and facile wet process technology. The lift-off micro-membrane LED showed 16% alleviated quantum efficiency droop under 200 mA/cm2 current injection, demonstrating the advantage of LED epitaxy exfoliation from the lattice-mismatched sapphire substrate. The origin of the performance improvement was investigated based on non-destructive characterization methods. Photoluminescence (PL) characterization showed a 7nm peak emission wavelength shift in the micro-membrane LED compared to the GaN-on-Sapphire LED. The Raman spectroscopy measurements correlate well with the PL observation that a 0.86 GPa relaxed compressive biaxial strain was achieved after the lift-off process. The micro-membrane LED technology enables further heterogeneous integration for forming pixelated red, green, blue (RGB) display on flexible and transparent substrate. The development of discrete and membrane LEDs using nano-fiber paper as the current spreading layer was also explored for such integration.
Advisors:
Ooi, Boon S. ( 0000-0001-9606-5578 )
Committee Member:
Hussain, Muhammad Mustafa ( 0000-0003-3279-0441 ) ; He, Jr-Hau ( 0000-0003-1886-9241 ) ; Ren, Fan
KAUST Department:
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Program:
Electrical Engineering
Issue Date:
May-2015
Type:
Thesis
Appears in Collections:
Theses; Electrical Engineering Program; Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.advisorOoi, Boon S.en
dc.contributor.authorLiao, Hsien-Yuen
dc.date.accessioned2015-05-19T05:52:29Zen
dc.date.available2015-05-19T05:52:29Zen
dc.date.issued2015-05en
dc.identifier.urihttp://hdl.handle.net/10754/554110en
dc.description.abstractDeveloping etching of GaN material system is the key to device fabrications. In this thesis, we report on the fabrication of high throughput lift-off of InGaN/GaN based micro-membrane light emitting diode (LED) from sapphire substrate using UV-assisted photoelectroless chemical (PEsC) etching. Unlike existing bandgap selective etching based on unconventional sacrificial layer, the current hydrofluoric acid based wet etching process enables the selective etching of undoped GaN layer already incorporated in standard commercial LED structures, thus attaining the leverage on high performance device design, and facile wet process technology. The lift-off micro-membrane LED showed 16% alleviated quantum efficiency droop under 200 mA/cm2 current injection, demonstrating the advantage of LED epitaxy exfoliation from the lattice-mismatched sapphire substrate. The origin of the performance improvement was investigated based on non-destructive characterization methods. Photoluminescence (PL) characterization showed a 7nm peak emission wavelength shift in the micro-membrane LED compared to the GaN-on-Sapphire LED. The Raman spectroscopy measurements correlate well with the PL observation that a 0.86 GPa relaxed compressive biaxial strain was achieved after the lift-off process. The micro-membrane LED technology enables further heterogeneous integration for forming pixelated red, green, blue (RGB) display on flexible and transparent substrate. The development of discrete and membrane LEDs using nano-fiber paper as the current spreading layer was also explored for such integration.en
dc.language.isoenen
dc.subjectGaNen
dc.subjectLight emitting diodes (LEDs)en
dc.subjectMembraneen
dc.subjectFlexible Displayen
dc.subjectEfficient Droopen
dc.subjectStrain Relaxationen
dc.titleFabrication and Characterization of Micro-membrane GaN Light Emitting Diodesen
dc.typeThesisen
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Divisionen
thesis.degree.grantorKing Abdullah University of Science and Technologyen_GB
dc.contributor.committeememberHussain, Muhammad Mustafaen
dc.contributor.committeememberHe, Jr-Hauen
dc.contributor.committeememberRen, Fanen
thesis.degree.disciplineElectrical Engineeringen
thesis.degree.nameMaster of Scienceen
dc.person.id129119en
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