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:20130121T074410Z UID:86564794-B4EE-1030-AD29-0050568D3657 DTSTART;TZID=Asia/Kolkata:20130122T170000 DTEND;TZID=Asia/Kolkata:20130122T180000 DESCRIPTION:Dept of EE announces an IEEE Seminar -------------------------- ---------- Jai Verma\, University of Notre Dame will speak on "MBE grown Q uantum-Dot UV Light Emitting Diodes with Tunnel-injection and Polarization -engineering" Where: DA 229\, ACES Building\, Dept of Electrical Engg. Whe n: Tuesday\, January 22\, 2013 What Time : 5 PM Refreshments will be serve d at 4:45 PM Abstract: ---------------------------- Immense progress has b een made in III-Nitride optical devices since the demonstration of blue la sers in mid 90’s. The attention of the solid state lighting has shi fted to longer wavelength (green)\, and to short wavelength (UV). At the s ame time\, major challenges remain in improving the efficiency of III-Nitr ide optical emitters. In this work\, we explore the many consequences of t he electronic polarization fields at heterojunctions of very short-λ li ght emitters. By using molecular beam epitaxy\, we grow III-Nitride hetero structures with high Al-composition AlGaN on AlN substrates for UV emitter s. A careful analysis of the role of polarization in heterostructures enab les us to design and demonstrate novel N-face QW LED heterostructure that incorporates polarization-induced doped p-type layers. These QWs emit phot ons near GaN QW band gap at room temperature. For shorter-λ emission\, we design and demonstrate a novel quantum-dot UV LED that uses tunnel-inje ction of carriers. This Q-dot UV LED emits at room temperature at ~240 nm. Both demonstrations help us identify unique opportunities for improvement s in short-wavelength III-Nitride LEDs and lasers of the future. These com pact light emitters are expected to enable numerous optoelectronic applica tions\, specifically those that lead to bio-photonic applications. Biograp hy: ------------------------------------------------ Jai Verma is a PhD ca ndidate at University of Notre Dame. His research interests are in Molecul ar Beam Epitaxy growth\, fabrication and analysis of III-Nitride based opt oelectronic devices. He received his Bachelor’s and Master’s degrees in Electrical Engineering from the Indian Institute of Technology Kanpur in 2008 where he had worked on P3HT:PCBM based organic solar cells . More recently he has been working on boosting the efficiency of III-Nitr ides Ultra-Violet Light Emitting diodes (UV LEDs) utilizing novel structur es comprising of polarization induced doping\, tunnel injection and quantu m dots. His research interests also include Transmission Electron Microsco pe analysis of III-Nitride device structures. He has published 24 papers i n noted scientific journals and conferences.\n\nCo-sponsored by: Dr. Kumar Vaibhav Srivastava\n\nSpeaker(s): \, \, \, \n\nRoom: DA 229\, Bldg: ACES\ , Department of Electrical Engineering\, Indian Institute of Technology Ka npur\, Kanpur\, Uttar Pradesh\, India\, 208016 LOCATION:Room: DA 229\, Bldg: ACES\, Department of Electrical Engineering\, Indian Institute of Technology Kanpur\, Kanpur\, Uttar Pradesh\, India\, 208016 ORGANIZER:kvs@iitk.ac.in SEQUENCE:0 SUMMARY:MBE grown Quantum-Dot UV Light Emitting Diodes with Tunnel-injectio n and Polarization-engineering URL;VALUE=URI:https://events.vtools.ieee.org/m/16363 X-ALT-DESC:Description: <br />\n Dept of EE announces an IEE E Seminar\n ------------------------------------\n\nJai Ver ma\,\nUniversity of Notre Dame\n\nwill speak on\n\n"MBE grown Quantum-Dot UV Light Emitting Diodes with Tunnel-injection and\nPolarization-engineeri ng"\n\nWhere: DA 229\, ACES Building\, Dept of Electrical Engg.\nWhen: Tue sday\, January 22\, 2013\nWhat Time : 5 PM\nRefreshments will be served at 4:45 PM\n\nAbstract:\n----------------------------\nImmense progress has been made in III-Nitride optical devices since the demonstration of blue l asers in mid 90’s. The attention of the solid state lighting has sh ifted to longer wavelength (green)\, and to short wavelength (UV). At the same time\, major challenges remain in improving the efficiency of III-Nit ride optical emitters. In this work\, we explore the many consequences of the electronic polarization fields at heterojunctions of very short-λ l ight emitters. By using molecular beam epitaxy\, we grow III-Nitride heter ostructures with high Al-composition AlGaN on AlN substrates for UV emitte rs. A careful analysis of the role of polarization in heterostructures ena bles us to design and demonstrate novel N-face QW LED heterostructure that incorporates polarization-induced doped p-type layers. These QWs emit pho tons near GaN QW band gap at room temperature. For shorter-λ emission\, we design and demonstrate a novel quantum-dot UV LED that uses tunnel-inj ection of carriers. This Q-dot UV LED emits at room temperature at ~240 nm . Both demonstrations help us identify unique opportunities for improvemen ts in short-wavelength III-Nitride LEDs and lasers of the future. These co mpact light emitters are expected to enable numerous optoelectronic applic ations\, specifically those that lead to bio-photonic applications.\n\nBio graphy:\n------------------------------------------------\nJai Verma is a PhD candidate at University of Notre Dame. His research interests are in M olecular Beam Epitaxy growth\, fabrication and analysis of III-Nitride bas ed optoelectronic devices. He received his Bachelor’s and Masterâ €™s degrees in Electrical Engineering from the Indian Institute of Tec hnology Kanpur in 2008 where he had worked on P3HT:PCBM based organic sola r cells. More recently he has been working on boosting the efficiency of I II-Nitrides Ultra-Violet Light Emitting diodes (UV LEDs) utilizing novel s tructures comprising of polarization induced doping\, tunnel injection and quantum dots. His research interests also include Transmission Electron M icroscope analysis of III-Nitride device structures. He has published 24 p apers in noted scientific journals and conferences.\n END:VEVENT END:VCALENDAR