The temperature of the optical phonon population is calculated by comparing the number of optical phonon to the number expected at a given temperature, which comes from the Bose-Einstein statistics.
12.
A higher optical phonon energy results in fewer optical phonons at a particular temperature, and there are therefore fewer scattering centers, and electrons in wide bandgap semiconductors can achieve high peak velocities.
13.
In addition this typical inefficiency, hot optical phonon populations tend to downconvert into multiple low-energy, acoustic phonon modes ( whereas photons typically do not downconvert into low energy infrared waves ).
14.
Local and spatial thermal non-equilibrium for the optical phonon and electron populations ( T _ { p, \ mathrm { O } } and T _ e ) for variations in the length.
15.
If the band gap and optical phonon mode are resonant, and the optical phonon tends to generate electrons, the phonovoltaic cell can approach the Carnot limit as T _ { pv } \ rightarrow 0.
16.
If the band gap and optical phonon mode are resonant, and the optical phonon tends to generate electrons, the phonovoltaic cell can approach the Carnot limit as T _ { pv } \ rightarrow 0.
17.
While the thermoelectric generator converts heat, a broad spectrum of phonon and electron energy, to electricity, the pV cell converts only a narrow band of phonon energy, i . e ., only the most energetic optical phonon modes.
18.
Where T _ \ mathrm { pV } is the temperature of the pV cell and T _ { p, \ mathrm { O } } is the temperature of the optical phonon population, as dictated by the Bose-Einstein statistics.
19.
Furthermore, the pV cell requires a material wherein a hot optical phonon prefers to produce an electron rather than multiple low energy acoustic phonons ( \ dot { \ gamma } _ { e-p } ^ * \ rightarrow 1 ).
20.
The resulting mobility is expected to be proportional to " T " " 3 / 2, while the mobility due to optical phonon scattering only is expected to be proportional to " T " " 1 / 2.
