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X-WR-CALNAME;VALUE=TEXT:糖心原创
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DTSTART:20141102T020000
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UID:calendar.24754.field_event_date.0@www.wright.edu
DTSTAMP:20260219T180927Z
CREATED:20141020T190923Z
DESCRIPTION:糖心原创 Physics Department Seminar\nFriday\, No
 vember 14\, 2014 at 3:00pm in 204 Fawcett\n\n'Advancing silicon photonics:
  Approaches to producing infrared active materials and devices on Si'\nBy 
 Jay Mathews\, Department of Physics and Electro-Optics Graduate Engineerin
 g Program\, University of Dayton\n\n______________________________________
 __\nABSTRACT: Silicon is the basis for a multi-billion dollar industry\, b
 ut its optical properties have limited its use in optoelectronics. Its hig
 h band gap prohibits optical absorption in much of the infrared\, and the 
 indirect nature of the band structure prevents it from being used as a sou
 rce for optical emission. Infrared optoelectronic devices realized directl
 y on Si could be used for photovoltaics\, infrared detection and imaging\,
  optical interconnects\, and infrared lasers.\n\nIn this talk\, I will dis
 cuss two different approaches to producing infrared materials and devices 
 compatible with conventional Si processing. First\, I will explore the epi
 taxial growth and properties of Sn-based Group IV alloys on Si substrates 
 using low pressure chemical vapor deposition (LPCVD). Materials with Sn co
 ntent up to 7% exhibit strong optical absorption and photoconductivity wel
 l below the band gap of Si\, and they have been used to fabricate prototyp
 e detectors with extended wavelength response\, as well as infrared LEDs. 
 More recently\, the Sn content in these films has been increased to near 1
 0%\, and the resulting films have a nearly direct band gap\, which could l
 ead to the fabrication of a new laser on Si.\n\nThe second approach I will
  discuss is the modification of the Si band structure through a process kn
 own as hyperdoping. Ion implantation of transition metals into Si is perfo
 rmed at very high doses\, followed by irradiation by a ns-scale UV laser p
 ulse that melts and resolidifies the implanted crystal. This process yield
 s single crystalline Si with very high amounts (orders of magnitude greate
 r than the solid solubilities) of impurities\, which can lead to the forma
 tion of an intermediate band in Si. The intermediate band can be used as a
 n intermediate transition between the valence and conduction bands of Si\,
  leading to enhanced absorption and photoconductivity well below the band 
 gap of Si.\n\nFinally\, I will discuss the method of transmission modulate
 d photoconductive decay (TMPCD) for measurement of recombination lifetimes
  in thin film semiconductor materials. This new technique will be used to 
 study charge dynamics in the Sn-based Group IV alloys and hyperdoped Si ma
 terials.\n\nBIO: Dr. Jay Mathews is currently an Assistant Professor in th
 e Department of Physics and the Electro-Optics Graduate Engineering Progra
 m at the University of Dayton. He obtained his BS with double major in Phy
 sics and Mathematics from Colorado State University in 2007\, and he recei
 ved his PhD in Physics from Arizona State University in 2011. Following gr
 aduation\, Dr. Mathews was awarded a fellowship in the National Academy of
  Sciences Research Associateship Program\, where he performed research for
  the US Army鈥檚 Benet Laboratories at Watervliet Arsenal in NY until July 2
 013. He started at University of Dayton in August 2013.
DTSTART;TZID=America/New_York:20141114T150000
DTEND;TZID=America/New_York:20141114T150000
LAST-MODIFIED:20150825T195407Z
LOCATION:204 Fawcett Hall
SUMMARY:Physics Seminar: Advancing silicon photonics: 'Approaches to produc
 ing infrared active materials and devices on Si'
URL;TYPE=URI:/events/physics-seminar-advancing-silico
 n-photonics-approaches-producing-infrared-active-materials
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