TY - JOUR
T1 - Non-equilibrium molecular-dynamics for impurities in semiconductors
T2 - Vibrational lifetimes and thermal conductivities
AU - Estreicher, S. K.
AU - Gibbons, T. M.
N1 - Funding Information:
This work is supported in part by the gant D-1126 from the R.A. Welch Foundation. Texas Tech's High Performance Computer Center provided generous amounts of CPU time.
PY - 2009/12/15
Y1 - 2009/12/15
N2 - Calculating from first principles the vibrational properties of impurities in semiconductors such as Si has kept theorists busy for more than a decade. The early focus has been on predicting IR- or Raman-active local vibrational modes, thus contributing to the identification of defects containing light impurities. However, the knowledge of the entire dynamical matrix of a supercell is precious. It allows the identification of all the localized modes in the system and the quantitative analysis of their degree of localization. It also allows the 'preparation' of a supercell in thermal equilibrium at non-zero temperatures without thermalization or thermostat. This allows non-equilibrium molecular-dynamics simulations to be performed with minimal temperature fluctuations. One application of this approach involves predicting the temperature dependence of vibrational lifetimes. Another application is the calculation of the impact of impurities on the thermal conductivity of semiconductor nanostructures. The approach involves preparing the supercell slightly off thermal equilibrium and then monitoring how its returns to equilibrium.
AB - Calculating from first principles the vibrational properties of impurities in semiconductors such as Si has kept theorists busy for more than a decade. The early focus has been on predicting IR- or Raman-active local vibrational modes, thus contributing to the identification of defects containing light impurities. However, the knowledge of the entire dynamical matrix of a supercell is precious. It allows the identification of all the localized modes in the system and the quantitative analysis of their degree of localization. It also allows the 'preparation' of a supercell in thermal equilibrium at non-zero temperatures without thermalization or thermostat. This allows non-equilibrium molecular-dynamics simulations to be performed with minimal temperature fluctuations. One application of this approach involves predicting the temperature dependence of vibrational lifetimes. Another application is the calculation of the impact of impurities on the thermal conductivity of semiconductor nanostructures. The approach involves preparing the supercell slightly off thermal equilibrium and then monitoring how its returns to equilibrium.
KW - Non-equilibrium molecular dynamics
KW - Thermal conductivity
KW - Vibrational properties of impurities
UR - http://www.scopus.com/inward/record.url?scp=74349094921&partnerID=8YFLogxK
U2 - 10.1016/j.physb.2009.08.102
DO - 10.1016/j.physb.2009.08.102
M3 - Article
AN - SCOPUS:74349094921
SN - 0921-4526
VL - 404
SP - 4509
EP - 4514
JO - Physica B: Condensed Matter
JF - Physica B: Condensed Matter
IS - 23-24
ER -