OSE General Chair, Dr. Daniel Feezell gives an invited paper on Carrier dynamics of polar, semipolar, and nonpolar InGaN/GaN LEDs measured by small-signal electroluminescence

Departmental News

Dr. Daniel Feezell 225x300

Posted: January 31, 2023


The carrier dynamics in InGaN/GaN LEDs are directly tied to their efficiency and maximum modulation speed, which are important metrics for solid-state lighting, displays, and optical communication. We measure the carrier dynamics of nonpolar, semipolar, and commercial c-plane InGaN/GaN LEDs using small-signal electroluminescence methods. Rate equations and a small-signal circuit are used to model the carrier dynamics. The model is fit to the optical frequency response and input impedance of the LEDs to extract the carrier lifetimes and the recombination rates. The results offer insight into the underlying causes of efficiency droop and the green gap and inform device design strategies.

Authors: Daniel Feezell, Arman Rashidi, Xuefeng Li, Mohsen Nami, Morteza Monavarian, Elizabeth DeJong, and Robert Armitage


Daniel Feezell is an Associate Professor and Regents’ Lecturer in the Electrical and Computer Engineering Department at the University of New Mexico. He received the Ph.D. degree in 2005 from the University of California Santa Barbara (UCSB) and was previously a Project Scientist in the Solid-State Lighting and Energy Center at UCSB and worked at Soraa. His research interests include epitaxial growth and fabrication of nonpolar and semipolar III-nitrides; high-efficiency and high-speed light-emitting diodes (LEDs); vertical-cavity surface-emitting lasers (VCSELs); nanoscale selective-area epitaxy; and wide-band-gap power electronics. He received a Defense Advanced Research Projects Agency (DARPA) Young Faculty Award and a National Science Foundation Faculty Early Career Development (CAREER) Award. He has authored or co-authored over 150 journal and conference publications and holds more than 25 US Patents.

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