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SUMMARY:Relaxation times of donor bound electrons in silicon and germanium
DTSTART;VALUE=DATE-TIME:20200714T104000Z
DTEND;VALUE=DATE-TIME:20200714T110000Z
DTSTAMP;VALUE=DATE-TIME:20260306T050748Z
UID:indico-contribution-1790@indico.inp.nsk.su
DESCRIPTION:Speakers: Roman Zhukavin (Institute for Physics of Microstruct
 ures)\nThe results of pump-probe experiments devoted to investigation of r
 elaxation of bound electrons in elemental semiconductors will be presented
 . The radiation of free electron lasers was used to excite the donor and m
 easure the relaxation times. Several donors were investigated to uundersta
 nd the common features as well as difference originated from different che
 mical nature of particular donor. The uniaxial stress was used to modify t
 he multivalley donor states. The typical relaxation times of bound electro
 ns while emitting acoustical phonons in silicon were measured to be in the
  range of hundreds or tens of picoseconds. The optical phonon assisted rel
 axation yields picosecond times. The applied stress allowed to suppess the
  relaxation rates in the case of the resonances with intervalley phonons. 
 In the case of donors in germanium the typical relaxation times are in the
  subnanosecond or nanosecond range. The binding energy of group-V donors i
 n germanium is less than optical phonons (10-14 meV) thus the intervalley 
 phonons which could influence the relaxation are of TA type. The stress ap
 plication to germanium crystal results in increase of lifetimes for some d
 onor states. For the case of Ge:As the pump-probe experiments allow to det
 ermine lifetime for 1s split off state. The latter result helps to suppose
  the possible inversion in the system under optical pumping.\n\nhttps://in
 dico.inp.nsk.su/event/24/contributions/1790/
LOCATION:Zoom Zoom 860 5034 1820
URL:https://indico.inp.nsk.su/event/24/contributions/1790/
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