III-V nitride semiconductor-based ultraviolet photodetectors

dc.contributor.advisorCampbell, Joe
dc.creatorYang, Bo, active 21st centuryen
dc.date.accessioned2015-05-14T18:43:08Zen
dc.date.accessioned2018-01-22T22:27:48Z
dc.date.available2015-05-14T18:43:08Zen
dc.date.available2018-01-22T22:27:48Z
dc.date.issued2003-12en
dc.descriptiontexten
dc.description.abstractVisible-blind and solar-blind ultraviolet photodetectors based on GaN/AlGaN were designed, fabricated, and characterized for commercial and military applications. High performance back-illuminated solar-blind MSM achieved external quantum efficiency of ~48%. The dark current of 40x40μm MSM was less than the instrument measurement limitation of 20fA for a bias <100V. No photoconductive gain was observed. With an n-type doped high-Al ratio "window" Al₀.₆Ga₀.₄N layer, back-illuminated solar-blind p-i-n photodiode achieved a quantum efficiency of ~55% at zero-bias. Absorption edge study of both MSM and p-i-n photodetectors, based on device spectral responses, resulted in a performance comparison of MSMs and p-i-ns, as the solar-blind photodetection requires a sharp solar-blind rejection. Photoconductive detectors and avalanche photodetectors, with the internal gain advantage, have been discussed as well. A 30μm diameter GaN avalanche photodiode achieved a gain >23, with a dark current less than 100pA. The breakdown showed a positive temperature coefficient of 0.03 V/K that is characteristic of avalanche breakdown. SiC APDs, as candidates for visible-blind applications, have been designed, fabricated and characterized. An avalanche gain higher than 10⁵, with a dark current less than 1nA, showed the potential of SiC APD replacing PMTs for high sensitivity visible-blind UV detection. A silicon-based optical receiver has been presented in the Appendix. With the photodiode internal avalanche gain ~4, a sensitivity ~-6.9dBm at 10Gbps has been achieved.en
dc.description.departmentElectrical and Computer Engineeringen
dc.format.mediumelectronicen
dc.identifier.urihttp://hdl.handle.net/2152/29863en
dc.language.isoengen
dc.rightsCopyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.en
dc.subjectVisible-blinden
dc.subjectSolar-blinden
dc.subjectUltraviolet photodetectorsen
dc.subjectGaN/AlGaNen
dc.subjectMilitary applicationsen
dc.subjectMSMen
dc.titleIII-V nitride semiconductor-based ultraviolet photodetectorsen
dc.typeThesisen

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