BEGIN:VCALENDAR VERSION:2.0 PRODID:IEEE vTools.Events//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:America/Los_Angeles BEGIN:DAYLIGHT DTSTART:20260308T030000 TZOFFSETFROM:-0800 TZOFFSETTO:-0700 RRULE:FREQ=YEARLY;BYDAY=2SU;BYMONTH=3 TZNAME:PDT END:DAYLIGHT BEGIN:STANDARD DTSTART:20251102T010000 TZOFFSETFROM:-0700 TZOFFSETTO:-0800 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=11 TZNAME:PST END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTAMP:20251109T235913Z UID:ECC07012-DDA6-41A3-A554-12D07CEDF00B DTSTART;TZID=America/Los_Angeles:20251107T114500 DTEND;TZID=America/Los_Angeles:20251107T131500 DESCRIPTION:Achieving efficient p-type doping in gallium nitride (GaN) and its alloys remains one of the most critical challenges in realizing the fu ll potential of III-nitride semiconductors for high-power electronics\, de ep-ultraviolet (DUV) optoelectronics\, and quantum information technologie s. While magnesium is the conventional acceptor dopant\, its high ionizati on energy (≈0.22 eV in GaN and up to 0.6 eV in AlN) limits hole concentr ations to below ~1% activation efficiency\, constraining device performanc e.\n\nOur recent work explores beryllium as an alternative acceptor in (Al \,Ga)N\, leveraging metal-organic chemical vapor deposition (MOCVD) to ach ieve high-quality\, low-defect epitaxial growth. Through extensive photolu minescence and time-resolved spectroscopy studies of over fifty MOCVD grow n Be-doped GaN samples\, we identified the UVLBe ​ band at ~3.38 eV as a signature of a shallow Be-related acceptor with an ionization energy of ~ 113–114 meV — significantly shallower than Mg in GaN. Complementary th eoretical studies support the assignment of this shallow state to the BeGa ​ONBeGa​ complex\, suggesting a pathway toward achieving p-type conduc tivity in AlGaN and even AlN alloys.\n\nIn recent limited MOCVD growth stu dies on co-doping with oxygen and Be\, we have observed preliminary indica tions that oxygen incorporation can enhance the signature of the shallow B e acceptor\, though further work is needed to fully establish the efficacy and stability of this co-doping strategy.\n\nThese results provide new in sight into the nature of Be-related defects in GaN and AlGaN\, and they hi ghlight co-doping pathways as a promising route to overcome the long-stand ing bottleneck of achieving high hole concentrations.\n\nWhen: Friday\, No vember 7th\, 2025 – 11:45AM to 1PM (PDT)\n\n11:45AM - 12PM: Intro\n12PM- 12:45PM: Lecture\n12:45PM-12:55PM: Q&A\n1PM Adjourn\n\nBio:\n\nDr. F. Shad i Shahedipour-Sandvik is a Professor of Engineering at the State Universit y of New York\, where she leads research on wide bandgap III-nitride semic onductor materials and devices for applications in lighting\, power electr onics\, sensing\, and quantum information science. Her work spans two deca des of innovation and pioneering work in (Al\,In) GaN materials and device engineering\, with contributions ranging from high-efficiency p-type dopi ng techniques and defect engineering and characterization to novel photoca thodes and betavoltaic devices. She has authored nearly 200 publications a nd delivered invited talks worldwide on growth\, characterization\, device physics with applications in emitters\, power electronics\, and detectors .\n\nShahedipour-Sandvik lab has been continuously funded by a variety of sources including NSF\, ARL/ARO\, DARPA\, DOE\, ARPA-E\, NASA\, and by ind ustry.\n\nShe has advised more than a dozen Ph.D. students\, many of whom now hold technical leadership positions in national labs\, and industry.\n \nShe served as Editor-in-Chief of the Journal of Electronic Materials (20 15–2024) and has been recognized with the SUNY Excellence in Research Aw ard and the IBM Faculty Award\, among other honors.\n\nVirtual: https://ev ents.vtools.ieee.org/m/502836 LOCATION:Virtual: https://events.vtools.ieee.org/m/502836 ORGANIZER:ieeescveds@gmail.com SEQUENCE:9 SUMMARY:From Mg to Be: Rethinking P-Type Doping Strategies in Wide-Bandgap III-Nitrides URL;VALUE=URI:https://events.vtools.ieee.org/m/502836 X-ALT-DESC:Description: <br /><p>Achieving efficient p-type doping in galli um nitride (GaN) and its alloys remains one of the most critical challenge s in realizing the full potential of III-nitride semiconductors for high-p ower electronics\, deep-ultraviolet (DUV) optoelectronics\, and quantum in formation technologies. While magnesium is the conventional acceptor dopan t\, its high ionization energy (&asymp\;0.22 eV in GaN and up to 0.6 eV in AlN) limits hole concentrations to below ~1% activation efficiency\, cons training device performance.</p>\n<p>Our recent work explores beryllium as an alternative acceptor in (Al\,Ga)N\, leveraging metal-organic chemical vapor deposition (MOCVD) to achieve high-quality\, low-defect epitaxial gr owth. Through extensive photoluminescence and time-resolved spectroscopy s tudies of over fifty MOCVD grown Be-doped GaN samples\, we identified the UVL<sub>Be</sub>&nbsp\;​ band at ~3.38 eV as a signature of a shallow Be -related acceptor with an ionization energy of ~113&ndash\;114 meV &mdash\ ; significantly shallower than Mg in GaN.&nbsp\; Complementary theoretical studies support the assignment of this shallow state to the Be<sub>Ga</su b>​O<sub>N</sub>Be<sub>Ga</sub>​ complex\, suggesting a pathway toward achieving p-type conductivity in AlGaN and even AlN alloys.&nbsp\;</p>\n< p>In recent limited MOCVD growth studies on co-doping with oxygen and Be\, we have observed preliminary indications that oxygen incorporation can en hance the signature of the shallow Be acceptor\, though further work is ne eded to fully establish the efficacy and stability of this co-doping strat egy.</p>\n<p>These results provide new insight into the nature of Be-relat ed defects in GaN and AlGaN\, and they highlight co-doping pathways as a p romising route to overcome the long-standing bottleneck of achieving high hole concentrations. &nbsp\;</p>\n<p class="MsoNormal">When: Friday\, Nove mber 7th\, 2025 &ndash\; 11:45AM to 1PM (PDT)&nbsp\;<br><br>11:45AM - 12PM : Intro&nbsp\;<br>12PM-12:45PM: Lecture <br>12:45PM-12:55PM: Q&amp\;A <br> 1PM Adjourn</p>\n<p class="MsoNormal">Bio:</p>\n<div>\n<p>Dr. F. Shadi Sha hedipour-Sandvik is a Professor of Engineering at the State University of New York\, where she leads research on wide bandgap III-nitride semiconduc tor materials and devices for applications in lighting\, power electronics \, sensing\, and quantum information science. Her work spans two decades o f innovation and pioneering work in (Al\,In) GaN materials and device engi neering\, with contributions ranging from high-efficiency p-type doping te chniques and defect engineering and characterization to novel photocathode s and betavoltaic devices. She has authored nearly 200 publications and de livered invited talks worldwide on growth\, characterization\, device phys ics with applications in emitters\, power electronics\, and detectors.</p> \n<p>Shahedipour-Sandvik lab has been continuously funded by a variety of sources including &nbsp\;NSF\, ARL/ARO\, DARPA\, DOE\, ARPA-E\, NASA\, and by industry.</p>\n<p>She has advised more than a dozen Ph.D. students\, m any of whom now hold technical leadership positions in national labs\, and industry.</p>\n<p>She served as Editor-in-Chief of the&nbsp\;<em>Journal of Electronic Materials</em> (2015&ndash\;2024) and has been recognized wi th the SUNY Excellence in Research Award and the IBM Faculty Award\, among other honors.</p>\n</div> END:VEVENT END:VCALENDAR