at room temperature intrinsic carrier concentration is higher in germa...
Carrier concentrations depends on the energy gap in the intrinsic semiconductor. In the case of Ge and Si the intrinsic carrier concentration of Ge is higher than that of Si because the energy gap in Ge is smaller than that of Si.
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at room temperature intrinsic carrier concentration is higher in germa...
Intrinsic Carrier Concentration in Germanium and Silicon at Room Temperature
Introduction:
Intrinsic carrier concentration refers to the concentration of charge carriers (electrons and holes) in a material when it is in a pure, undoped state. The intrinsic carrier concentration is an important parameter in semiconductor physics as it determines the material's electrical conductivity. Germanium (Ge) and silicon (Si) are two commonly used semiconductor materials. At room temperature, the intrinsic carrier concentration in germanium is higher than in silicon. This can be attributed to the smaller energy gap in germanium compared to silicon.
Explanation:
1. Carrier mobility:
- Carrier mobility refers to the ease with which charge carriers move through a material under the influence of an electric field.
- Option 'A' suggests that carrier mobilities are higher in germanium than in silicon. However, carrier mobility is not directly related to intrinsic carrier concentration.
2. Energy gap:
- The energy gap, also known as the bandgap, is the energy difference between the valence band and the conduction band in a semiconductor material.
- Option 'B' states that the energy gap in germanium is smaller than that in silicon, which is correct.
- Germanium has a smaller energy gap of approximately 0.67 eV, while silicon has a larger energy gap of approximately 1.1 eV.
- The smaller energy gap in germanium allows for a higher probability of thermal excitation, leading to a higher intrinsic carrier concentration at room temperature.
3. Atomic number and atomic weight:
- Options 'C' and 'D' suggest that the atomic number and atomic weight of germanium are larger than silicon.
- While these factors may contribute to certain material properties, they are not directly related to intrinsic carrier concentration.
Conclusion:
The correct answer is option 'B' - the energy gap in germanium is smaller than that in silicon. This smaller energy gap allows for a higher intrinsic carrier concentration in germanium at room temperature.
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