MateriAlZ Seminar: Steven DenBaars
Friday, October 14, 2022, 10:50 a.m., Arizona Time
Steven DenBaars
Distinguished Professor of Materials and Electrical and Computer Engineering
Mitsubishi Chemical Professor in Solid State Lighting & Display
Executive Director of the Solid State Lighting and Energy Electronics Center (SSLEEC)
The University of California, Santa Barbara
"Advanced III-Nitride Semiconductor Devices for Visible Photonics and Power Electronics"
Zoom link | Passcode: 309253
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Abstract
The developments of high performance AlInGaN based LEDs, Laser and III-Nitride high electron mobility transistors (HEMTs) are discussed. Through novel epitaxial growth and processing, and transparent packaging Professor DenBaars achieved external quantum efficiencies as high as 58% EQE for blue microLEDs. Using ultra-wide band gap (UWBG) AlGaN compounds emission wavelength of 240-330nm have been achieved. In the UVC region the MOCVD growth on low dislocation density AlN/sapphire substrates has enabled him to increase the quantum efficiencies dramatically up to 10% at 285nm. By optimizing growth on AlN/sapphire substrates defect densities as low as 1E+8cm-2 have been demonstrated. Using strain relaxation methods Professor DenBaars has also extending the wavelength range of the InGaN alloys well into the red spectrum with emission as long as 640nm. Red InGaN based red MicroLEDs with efficiencies of 6% has been fabricated, and they display superior temperature performance in comparison to AlGaInP based devices.The III-Nitride materials have also proven to be indispensable for obtaining high power RF devices as well. Using AlN interlayers and high purity metalorganics he has achieved mobilities of 1500 V/cm2-sec, with high sheet charges of 2e+13 cm-2.
Bio
Steven DenBaars is a Distinguished Professor of materials and electrical and computer engineering, The Mitsubishi Chemical Professor in solid state lighting & display, and Executive Director of the Solid State Lighting and Energy Electronics Center (SSLEEC) at the University of California, Santa Barbara. Professor DenBaars received his BS from the University of Arizona in metallurgical engineering, MS and PhD in electrical engineering from the University of Southern California in 1988. Specific research interests include growth of wide-bandgap semiconductors (GaN based), and their application to Blue LEDs and lasers and high power electronic devices. Prof. DenBaars has been an active in entrepreneurship, having helped co-found Nitres Inc., Soraa Laser Diode (SLD), and Akoustis Technologies Inc., in the field of III-Nitride optoelectronics and electronics. He received the IEEE Fellow award in 2005, Aron Kressel Award – IEEE Photonics Society, elected member of the National Academy of Engineers 2012, and National Academy of Inventors in 2014. He has authored or co-authored over 980 technical publications, 350 conference presentations, and been cited over 85,000 times (Goggle Scholar H-index =143).