Subpicosecond time-resolved Raman studies of nonequilibrium excitations in wurtzite GaN
- Arizona State Univ., Tempe, AZ (United States). Dept. of Physics and Astronomy
- Old Dominion Univ., Norfolk, VA (United States). Dept. of Electrical Engineering
- Univ. of Illinois, Urbana, IL (United States). Coordinated Science Lab.
Non-equilibrium electron distributions as well as phonon dynamics in wurtzite GaN have been measured by subpicosecond time-resolved Raman spectroscopy. The experimental results have demonstrated that for electron densities n {ge} 5 {times} 10{sup 17} cm{sup {minus}3}, the non-equilibrium electron distributions in wurtzite GaN can be very well described by Fermi-Dirac distribution functions with the temperature of electrons substantially higher than that of the lattice. The population relaxation time of longitudinal optical phonons was directly measured to be {tau} {approx_equal} 5 {+-} 1 ps at T = 25 K. The experimental results on the temperature dependence of the lifetime of longitudinal optical phonons suggest that the primary decay channels for these phonons are the decay into (1) one transverse optical phonon and one high energy, longitudinal or transverse acoustical phonons; and (2) one transverse optical phonon and one E{sub 2} phonon.
- Sponsoring Organization:
- National Science Foundation, Washington, DC (United States)
- OSTI ID:
- 585814
- Report Number(s):
- CONF-961202--; ISBN 1-55899-353-3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Picosecond Raman studies of electron-phonon interactions in the wide bandgap semiconductor GaN
Nanoscale size dependence parameters on lattice thermal conductivity of Wurtzite GaN nanowires