Alexandria Digital Research Library

Hybrid MOCVD/MBE III-Nitride tunnel junctions

Author:
Yonkee, Benjamin Philip
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:
2016
Issued Date:
2016
Topics:
Materials science
Genres:
Dissertations, Academic and Online resources
Dissertation:
Ph.D.--University of California, Santa Barbara, 2016
Description:

The efficiency of GaN LEDs is limited by the poor electrical properties of p-GaN which necessitate a transparent conducting oxide (TCO) or silver based mirror as a p-contact. GaN tunnel junctions would eliminate the need for a standard p-contact but have been difficult to realize due to difficulty in achieving the high doping densities required. Several groups have fabricated GaN tunnel junctions using polarization induced band bending from an InGaN layer to reduce the doping densities required. While the InGaN layer allows for effective tunneling, it also adds optical loss which would reduce the light extraction of LEDs with this technology. An additional barrier to this is the lack of p-type conductivity from as MOCVD grown Mg:GaN which requires a thermal anneal to remove hydrogen. Because n-GaN acts as a hydrogen diffusion barrier, MOCVD tunnel junctions are greatly limited in their growth and applications. A technique was developed to produce III-nitride tunnel junctions without the need for a post growth activation by combining the MOCVD and MBE growth techniques. Because the p-GaN is activated in situ, no further sidewall activation is needed. Doping densities of up to 2 x 1020 cm -3 for both Si and Mg doped GaN are obtained using this technique. Using this hybrid growth technique, LEDs and edge emitting laser diodes were demonstrated.

Physical Description:
1 online resource (136 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f3sf2wbd
ISBN:
9781369576382
Catalog System Number:
990047512370203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Benjamin Yonkee
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