Steven P. DenBaars

UC Santa Barbara

Photo of Steven P. DenBaars

(AlGaBIn)N Based Materials for UV Emitting Photonic Devices

The AlGaN material system allows great flexibility in tuning UV light emission from LEDs and laser to wavelengths spanning 200nm to 390nm. Recently, we have demonstrated UV-C LEDs emitting at 270nm with powers as high as 7mW and 5% external quantum efficiency(EQE). At these levels the LEDs already show great promise in sterilizing COVID-19 in air, water, and surface decontamination. However, the high Al composition in the LEDs leads to high dislocation densities(1E+9 cm-2) and strong piezoelectric effects which hinder the efficiency and performance. By incorporating other elements such as B and In in the AlGaN alloys, lattice matched and strain and piezoelectric free structures can be achieved. Additionally, if bulk AlN substrates can be grown with low defect densities, UV lasers and high power electronic devices can also be realized. The advent of bulk AlN crystal would also enable other crystal planes in semi-polar and non-polar orientations to be incorporated into active devices. These materials improvements would be key developments in realizing UV photonic devices with greater than 60% EQE and high power operation. This work was supported by the Solid State Lighting and Energy Electronics Center(SSLEEC).


Dr. Steven P. DenBaars is a Professor of Materials and Co-Director of the Solid-State Lighting and Energy Electronics Center (SSLEEC) at the University of California Santa Barbara. Specific research interests include growth of wide-bandgap semiconductors (III-Nitride based), and their application to UV, Blue and Green LEDs and lasers and high power GaN electronic devices. Prof. DenBaars has been an active in entrepreneurship, having co-founded 3 start-up companies 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 Engineering 2012, and National Academy of Inventors in 2014. He has authored or co-authored over 1100 technical publications (with an h-index of 105), 350 conference presentations, and over 150 U.S. patents.