Topic: Electronic Devices and Circuits
Which of the following correctly describes the temperature dependence of carrier mobility ($\mu$) in a non-degenerate n-type semiconductor?
- A. $\mu$ increases with T due to increased phonon scattering
- B. $\mu$ decreases with T due to decreased lattice scattering
- C. $\mu$ decreases with T due to increased lattice scattering
- D. $\mu$ is independent of temperature
Answer: C. $\mu$ decreases with T due to increased lattice scattering
Explanation: At moderate to high temperatures (like room temperature), carrier mobility in a semiconductor is predominantly limited by lattice scattering (also called phonon scattering). As temperature $T$ increases, thermal vibrations of the crystal lattice increase, causing more frequent collisions and increasing scattering. This results in decreased carrier mobility ($\mu \propto T^{-3/2}$).