111,349 research outputs found
Thermoelectric properties of -type SrTiO3
We present an investigation of the thermoelectric properties of cubic
perovskite SrTiO3. The results are derived from a combination of calculated
transport functions obtained from Boltzmann transport theory in the constant
scattering time approximation based on the electronic structure and existing
experimental data for La-doped SrTiO3. The figure of merit ZT is modeled with
respect to carrier concentration and temperature. The model predicts a
relatively high at optimized doping, and suggests that the value can
reach 0.7 at T = 1400 K. Thus can be improved from the current
experimental values by carrier concentration optimization
Proton-produced defects in n-type silicon
Defect energy levels and concentrations for proton irradiated, n-type silicon single crystal
Spin relaxation in -type ZnO quantum wells
We perform an investigation on the spin relaxation for -type ZnO (0001)
quantum wells by numerically solving the kinetic spin Bloch equations with all
the relevant scattering explicitly included. We show the temperature and
electron density dependence of the spin relaxation time under various
conditions such as impurity density, well width, and external electric field.
We find a peak in the temperature dependence of the spin relaxation time at low
impurity density. This peak can survive even at 100 K, much higher than the
prediction and measurement value in GaAs. There also exhibits a peak in the
electron density dependence at low temperature. These two peaks originate from
the nonmonotonic temperature and electron density dependence of the Coulomb
scattering. The spin relaxation time can reach the order of nanosecond at low
temperature and high impurity density.Comment: 6 pages, 4 figure
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