why does the resistivity of semiconductors decreases with temperature ?
why does the resistivity of semiconductors decreases with temperature ?
Conductivity of a material is determined by two factors: the concentration of free carriers available to conduct current and their mobility (or freedom to move). In a semiconductor, both mobility and carrier concentration are temperature dependent.
At absolute zero temperature any semiconductor (Si or Ge) behaves as an insulator. Some electron-hole pairs may get generated due to thermal energy at room temperature (300 K). At higher temperature, more electron-hole pairs are generated. The concentration of charge carriers will be higher at higher temperature. Thus, the conductivity of intrinsic semiconductor increases with increasing temperature and the resistivity decreases with increase in the temperature.
Conductivity of a material is determined by two factors: the concentration of free carriers available to conduct current and their mobility (or freedom to move). In a semiconductor, both mobility and carrier concentration are temperature dependent.
At absolute zero temperature any semiconductor (Si or Ge) behaves as an insulator. Some electron-hole pairs may get generated due to thermal energy at room temperature (300 K). At higher temperature, more electron-hole pairs are generated. The concentration of charge carriers will be higher at higher temperature. Thus, the conductivity of intrinsic semiconductor increases with increasing temperature and the resistivity decreases with increase in the temperature.
