Carrier Transport Phenomena

What is the primary mechanism for carrier motion in a semiconductor under an electric field?

• Thermal excitation
• Drift
• Diffusion
• Scattering

Which mechanism involves movement of carriers from high concentration to low concentration?

• Injection
• Recombination
• Diffusion
• Drift

What does mobility (μ) represent in semiconductor physics?

• Carrier lifetime
• Carrier generation rate
• Carrier speed
• Ease of carrier movement in electric field

Which unit is used to express carrier mobility?

• cm²/V·s
• A/cm²
• V/cm
• S/cm

What is the relation between drift current and electric field?

• Directly proportional
• Inversely proportional
• Logarithmic
• No relation

Which factor does NOT affect carrier mobility?

• Impurity scattering
• Lattice temperature
• Electric field polarity
• Crystal defects

Which law relates diffusion current density to the concentration gradient?

• Faraday’s Law
• Ohm’s Law
• Einstein Relation
• Fick’s Law

What does the Einstein relation connect?

• Mobility and temperature
• Electric field and mobility
• Diffusion coefficient and mobility
• Conductivity and resistivity

What type of current results from the application of a voltage across a semiconductor?

• Recombination current
• Drift current
• Diffusion current
• Saturation current

In n-type semiconductors, the majority carriers are:

• Holes
• Electrons
• Ions
• Excitons