BEGIN:VCALENDAR VERSION:2.0 PRODID:IEEE vTools.Events//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:Asia/Kolkata BEGIN:STANDARD DTSTART:19451014T230000 TZOFFSETFROM:+0630 TZOFFSETTO:+0530 TZNAME:IST END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTAMP:20230423T125405Z UID:EEE4CA02-09C9-4670-853C-DE5EFA692EC7 DTSTART;TZID=Asia/Kolkata:20230419T130000 DTEND;TZID=Asia/Kolkata:20230419T140000 DESCRIPTION:April 19\, 2023 @ 01:00 pm\nBandgap Engineering and Device Appl ications of Dilute Nitrides\nCharles W. Tu\nDepartment of Electrical Engin eering\, National Chung Hsing University\, Taichung\, TAIWAN\n\nIncorporat ing ~1% nitrogen into GaAs\, InP\, and GaP results in a large bandgap bowi ng\, a large change of conduction band lineup\, and in GaP even a large ch ange in the band structure from indirect to direct bandgap. These three ba ndgap engineering parameters from dilute nitrides are used to improve the performance of electrical\, optoelectronic\, and photovoltaic devices. (1) When GaInNAs is used as the base of a GaAs heterojunction bipolar transis tor (HBT)\, the turn-on voltage is lowered than that of GaAs-base and GaIn As-base HBT due to the smaller bandgap. (2) Similarly\, GaInNAs can be lat tice-matched to GaAs and can improve the conversion efficiency of a multij unction solar cell. (3) Incorporating 0.5% of N into GaP results in a dire ct band gap material. Thus\, GaNP solar cells achieve 3 times the conversi on efficiency at one quarter of the thickness when compared to GaP solar c ells. (4) When InNAsP is the quantum well of an InNAsP/GaInAsP optically p umped quantum-well microcavity laser\, the light output is larger than tha t of GaInAs/GaInAsP counterpart due to the larger conduction-band offset. (5) Similarly\, the light output of a GaNP/GaP light-emitting diode (LED) is larger than that of an AlGaInP/GaAs LED at the same wavelength. (6) Wit h the introduction of iPhone X in 2017\, which incorporates several vertic al-cavity surface-emitting lasers (VCSELs) for facial recognition\, long-w avelength (1550 nm) VCSELs have aroused a new interest in dilute nitride G aInNAsSb sandwiched between top and bottom GaAs/AlAs Distributed Bragg Ref lectors (DBRs) for eye-safety and cost reasons.\n\nCharles Tu is a Yushan (Monte Jade) Fellow and Research Professor in the Department of Electrical Engineering\, National Chung Hsing University in Taichung\, Taiwan\, and he is also a Distinguished Professor Emeritus in the Department of Electri cal and Computer Engineering (ECE) at University of California\, San Diego . He was in the UCSD faculty from 1988 to 2018\, was the ECE Department Ch air from 1999 to 2003\, and was an Associate Dean of the Jacobs School of Engineering from 2004 to 2013. Tu's research interests include novel compo und semiconductor heterostructures and nanostructures for electronic\, opt oelectronic and photovoltaic applications. He was a Distinguished Member o f Technical Staff at AT&T Bell Laboratories\, Murray Hill\, New Jersey fro m 1980 to 1988. He earned his Ph.D. in Engineering and Applied Science fro m Yale and his B.Sc. (Hon.) in Physics from McGill University in Montreal. Tu is a Fellow of the IEEE\, American Physical Society\, and AVS Science and Technology Society. He received Taiwan's Pan Wen-Yuan Foundation Outst anding Research Award in 2009\, the North American MBE Innovator Award in 2011\, an honorary doctorate from Linköping University\, Sweden in 2013\, and the IEEE Region 6 (Western U.S.) Educator of the Year Award in 2014.\ n\nCo-sponsored by: Deen Dayal Upadhyaya College\, University of Delhi\n\n Agenda: \nApril 19\, 2023 @ 01:00 pm\nBandgap Engineering and Device Appli cations of Dilute Nitrides\nCharles W. Tu\nDepartment of Electrical Engine ering\, National Chung Hsing University\, Taichung\, TAIWAN\n\nVirtual: ht tps://events.vtools.ieee.org/m/358962 LOCATION:Virtual: https://events.vtools.ieee.org/m/358962 ORGANIZER:msaxena@ieee.org SEQUENCE:0 SUMMARY:Webinar Series by Leading IEEE Electron Device Luminaries URL;VALUE=URI:https://events.vtools.ieee.org/m/358962 X-ALT-DESC:Description: <br /><p>April 19\, 2023 @ 01:00 pm<br />Bandgap En gineering and Device Applications of Dilute Nitrides<br />Charles W. Tu<br />Department of Electrical Engineering\, National Chung Hsing University\ , Taichung\, TAIWAN</p>\n<p>Incorporating ~1% nitrogen into GaAs\, InP\, a nd GaP results in a large bandgap bowing\, a large change of conduction ba nd lineup\, and in GaP even a large change in the band structure from indi rect to direct bandgap. These three bandgap engineering parameters from di lute nitrides are used to improve the performance of electrical\, optoelec tronic\, and photovoltaic devices. (1) When GaInNAs is used as the base of a GaAs heterojunction bipolar transistor (HBT)\, the turn-on voltage is l owered than that of GaAs-base and GaInAs-base HBT due to the smaller bandg ap. (2) Similarly\, GaInNAs can be lattice-matched to GaAs and can improve the conversion efficiency of a multijunction solar cell. (3) Incorporatin g 0.5% of N into GaP results in a direct band gap material. Thus\, GaNP so lar cells achieve 3 times the conversion efficiency at one quarter of the thickness when compared to GaP solar cells. (4) When InNAsP is the quantum well of an InNAsP/GaInAsP optically pumped quantum-well microcavity laser \, the light output is larger than that of GaInAs/GaInAsP counterpart due to the larger conduction-band offset. (5) Similarly\, the light output of a GaNP/GaP light-emitting diode (LED) is larger than that of an AlGaInP/Ga As LED at the same wavelength. (6) With the introduction of iPhone X in 20 17\, which incorporates several vertical-cavity surface-emitting lasers (V CSELs) for facial recognition\, long-wavelength (1550 nm) VCSELs have arou sed a new interest in dilute nitride GaInNAsSb sandwiched between top and bottom GaAs/AlAs Distributed Bragg Reflectors (DBRs) for eye-safety and co st reasons.&nbsp\;</p>\n<p>Charles Tu is a Yushan (Monte Jade) Fellow and Research Professor in the Department of Electrical Engineering\, National Chung Hsing University in Taichung\, Taiwan\, and he is also a Distinguish ed Professor Emeritus in the Department of Electrical and Computer Enginee ring (ECE) at University of California\, San Diego. He was in the UCSD fac ulty from 1988 to 2018\, was the ECE Department Chair from 1999 to 2003\, and was an Associate Dean of the Jacobs School of Engineering from 2004 to 2013. Tu's research interests include novel compound semiconductor hetero structures and nanostructures for electronic\, optoelectronic and photovol taic applications. He was a Distinguished Member of Technical Staff at AT& amp\;T Bell Laboratories\, Murray Hill\, New Jersey from 1980 to 1988. He earned his Ph.D. in Engineering and Applied Science from Yale and his B.Sc . (Hon.) in Physics from McGill University in Montreal. Tu is a Fellow of the IEEE\, American Physical Society\, and AVS Science and Technology Soci ety. He received Taiwan's Pan Wen-Yuan Foundation Outstanding Research Awa rd in 2009\, the North American MBE Innovator Award in 2011\, an honorary doctorate from Link&ouml\;ping University\, Sweden in 2013\, and the IEEE Region 6 (Western U.S.) Educator of the Year Award in 2014.</p><br /><br / >Agenda: <br /><p>April 19\, 2023 @ 01:00 pm<br />Bandgap Engineering and Device Applications of Dilute Nitrides<br />Charles W. Tu<br />Department of Electrical Engineering\, National Chung Hsing University\, Taichung\, T AIWAN</p> END:VEVENT END:VCALENDAR