AlGaN-based UV lasers and LEDs

Time: Thursday, September 19, 2019 - 2:00pm - 3:00pm
Type: Seminar Series
Presenter: Xiaohang Li; Advanced Semiconductor Laboratory; Electrical Engineering Program and Applied Physics Program, King Abdullah University of Science and Technology (KAUST)
Room/Office: Room 107
Location:
J. Robert Mann, Jr. Engineering Student Center
10 Hillhouse Avenue
New Haven, CT 06511
United States

Department of Electrical Engineering Seminar Series 

AlGaN-based UV lasers and LEDs

Xiaohang Li, Ph.D.
Advanced Semiconductor Laboratory
Electrical Engineering Program and Applied Physics Program
King Abdullah University of Science and Technology (KAUST), Saudi Arabia

Abstract:
III-nitride visible lasers and LEDs have demonstrated enormous success in solid state lighting and display with wall-plug efficiency close to 90%. However, III-nitride UV lasers and LEDs still suffer much lower efficiency due to multi-faceted challenges, hindering them from being deployed in critical areas including water purification, curing, and communication. This seminar elaborates the research progress made by Advanced Semiconductor Laboratory at KAUST to improve the performance of the UV lasers and LEDs, including epitaxy, polarization physics, and devices. Also, the seminar would cover the first deep UV lasing from GaN quantum wells and the first III-nitride design software based on machine learning.

Bio:
Xiaohang Li is an Assistant Professor at KAUST and the founder of Polarization Toolbox. Prior to joining KAUST, he received B.S., M.S., and Ph.D. degrees from Huazhong University of Science and Technology, Lehigh University, and Georgia Institute of Technology, respectively. He is the recipient of the Harold M. Manasevit Young Investigator Award from the American Association for Crystal Growth, the SPIE D. J. Lovell Scholarship, the Edison Prize from the Edison Innovation Foundation, and the IEEE Photonics Graduate Student Fellowship. He is also an Associate Editor of the OSA Photonics Research.

References
1. M. Shan et al., “Deep UV laser at 249 nm based on GaN quantum wells,” ACS Photonics accepted (2019).
2. W. Guo et al., "Three-dimensional band diagram in lateral polarity junction III-nitride heterostructures," Optica 6, 1058 (2019).
3. Z. Ren et al., “III-nitride deep UV LED without electron blocking layer,” IEEE Photon. J. 11, 8200511 (2019).
4. H. Sun et al., "Graded-Index Separated Confinement Heterostructure AlGaN Nanowires: Towards Ultraviolet Laser Diodes Implementation," ACS Photon. 5, 3305 (2018).
5. W. Guo et al. "Lateral-Polarity-Structure of AlGaN Quantum Wells: A Promising Approach for Enhancing the Ultraviolet Luminescence," Adv. Funct. Mater. 28, 1802395 (2018).
6. H. Sun et al. "Surface-Passivated AlGaN Nanowires for Enhanced Luminescence of Ultraviolet Light Emitting Diodes," ACS Photon. 5, 964 (2018).
7. K. Liu et al., "Wurtzite BAlN and BGaN alloys for heterointerface polarization engineering," Appl. Phys. Lett. 111 (22), 222106 (2017).
8. H. Sun et al., “Influence of TMAl preflow on AlN epitaxy on sapphire,” Appl. Phys. Lett. 110, 192106 (2017).
9. B. Janjua et al., “Droop-free AlxGa1-xN/AlyGa1-yN quantum-disks-in-nanowires ultraviolet LED emitting at 337 nm on metal/silicon substrates”, Opt. Express 25, 2 (2017).
10. B. Janjua et al., “Self-planarized quantum-disks nanowires ultraviolet-B emitter utilizing pendeo-epitaxy,” Nanoscale 9, 7805 (2017).
11. https://polarizationtoolbox.com

Thursday, September 19, 2019
4:00 PM - Mann Student Center
10 Hillhouse Avenue, Room 107