The effect of phonon drag of charge carriers in $In_{1-x}Ga_xSb$

Özet

The temperature dependencies of the thermal power $a_0$ and thermal conductivity $\kappa$ in two samples of $In_{1-x }Ga_xSb$ (x=0.65 and 0.45) doped by $Te\sim$ 0.001 at\%, with electron concentration n = 5.9 .$10^{16}$ and 1.3 . $10^{17} cm^ {-3}$ (at 100K), have been investigated. It is shown that in $In_{0.35}Ga_{0.65}Sb$ $a_0$ increases with decreasing T below 50K. At 14K $a_0$ passes through maximum and it falls sharply with decreasing T. It is shown that the maximum value of $a_0$ is in agreement with the maximum value of $\kappa$ . In $In_{0.55}Ga_{0.45}Sb$, starting from T = 4.2K, $a_0$ is shown to increase monotonically. For $In_{0.35}Ga_{0.65}Sb$, thermal power due to phonon drag $\alpha_{ph}$ is derived and its dependence on temperature, $\alpha_{ph}(T)$, is plotted. It is shown that when aph rises with decreasing T, $\alpha_{ph}(T)$ changes as $T^{-2.6}$; and when the curve falls, it is characterized by a power index of 2.8. These results for $In_{0.35}Ga_{0.65}Sb$ compare reasonably well to other semiconductors for solid solutions and are in good agreement with Herring theory.