Browsing by Subject "Phonon emissions"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Temperature dependent energy relaxation time in AlGaN/AlN/GaN heterostructures
    (2012) Tiras, E.; Celik O.; Mutlu, S.; Ardali, S.; Lisesivdin, S.B.; Özbay, Ekmel
    The two-dimensional (2D) electron energy relaxation in Al 0.25Ga 0.75N/AlN/GaN heterostructures was investigated experimentally by using two experimental techniques; Shubnikov-de Haas (SdH) effect and classical Hall Effect. The electron temperature (T e) of hot electrons was obtained from the lattice temperature (T L) and the applied electric field dependencies of the amplitude of SdH oscillations and Hall mobility. The experimental results for the electron temperature dependence of power loss are also compared with the current theoretical models for power loss in 2D semiconductors. The power loss that was determined from the SdH measurements indicates that the energy relaxation of electrons is due to acoustic phonon emission via unscreened piezoelectric interaction. In addition, the power loss from the electrons obtained from Hall mobility for electron temperatures in the range T e > 100 K is associated with optical phonon emission. The temperature dependent energy relaxation time in Al 0.25Ga 0.75N/AlN/GaN heterostructures that was determined from the power loss data indicates that hot electrons relax spontaneously with MHz to THz emission with increasing temperatures. © 2012 Elsevier Ltd. All rights reserved.
  • Thumbnail Image
    ItemOpen Access
    Theoretical investigations on the energy relaxation in two-dimensional GaN systems
    (Wiley, 2007) Taş, Murat; Tanatar, Bilal
    We theoretically study the energy relaxation of hot electrons via LO-phonon emission in two-dimensional GaN systems. We employ a model in which electrons and the lattice are in equilibrium separately, and the effective electron temperature is much larger than the lattice temperature. We include the dynamical screening of electrons, electron-phonon interactions reduced phonon self-energy correction, the hot-phonon, and the finite-size effects. The power loss to acoustic phonons is also considered.