BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Electrostatic manipulation of self-assembled InAs/GaAs quantum dot
 s (QDs) and interface fluctuation GaAs/AlAs QDs (IF-QDs) by focused laser 
 assisted diffusion of Manganese interstitial ions in GaAs/AlAs/GaMnAs reso
 nant tunnelling diode (RTD) structures - Dr Ateeq Nasir\, Cavendish Labora
 tory\, University of Cambridge
DTSTART:20140602T131500Z
DTEND:20140602T141500Z
UID:TALK52317@talks.cam.ac.uk
CONTACT:Teri Bartlett
DESCRIPTION:The effect of locally introducing small clusters of interstiti
 al Manganese ions near both IF-QDs and InAs/GaAs QDs embedded within GaAs/
 AlAs/GaMnAs pin-RTDs has been studied. Experiments and simulations show th
 at the microscopic random fluctuations in the electric field generated by 
 these ions can be as strong as 200 kV/cm (in the growth direction) and 40 
 kV/cm (in the growth plane) in the plane of the QD. The resulting shifts i
 n the quantum confined Stark effect of the weakly confined IF-QDs have bee
 n used to optically probe such nanoscale potential fluctuations [1]. \nThe
  local introduction of these charges by focused laser assisted diffusion n
 ear InAs/GaAs-QDs have demonstrated site-specific\, electrically driven\, 
 bright few QD-nano-LEDs. We have also been able to locally manipulate carr
 ier relaxation processes from excited wetting layer states into the InAs/G
 aAs QD by the nanoscale electrostatic preferential current channelling phe
 nomena (or nanoLED) previously reported in such pin-RTD structures [2\,3].
 \n\n[1] A. Nasir et.al.\, Phys. Rev. B. 85\, 195317  (2012)\n[2] F. Intont
 i et.al.\, Appl. Phys. Lett. 98\, 183102 (2011)\n[3] O. Makarovsky et.al.\
 , Advanced Materials 22\, 3176 (2010\n
LOCATION:Mott Seminar Room\, Cavendish Laboratory\, Department of Physics
END:VEVENT
END:VCALENDAR