1.7. Drift and Diffusion Currents

Try these first

1. 1.

   What is drift current?

   Hint

   Think of how cars move on a highway when there's a push.

2. 2.

   What causes diffusion current?

   Hint

   It’s like a crowd dispersing from a packed party.

3. 3.

   What is the primary cause of drift current?

   • Concentration gradient
   • Electric field
   • Temperature

   Hint

   Recall what propels charge carriers in a semiconductor.

4. 4.

   True or False: Diffusion current occurs due to electric fields.

   • True
   • False

   Hint

   Think about what makes charge carriers move.

5. 5.

   If a semiconductor has a drift current of 5 mA due to an electric field of 10 V/m and a mobility of 1500 cm²/(V·s), calculate the carrier concentration (n).

   Hint

   Remember to convert units consistently.

6. 6.

   A semiconductor reaches equilibrium with both drift and diffusion currents. If the drift current is 3 mA and the diffusion current is 2 mA, what is the net current?

   Hint

   If currents are in the opposite direction, remember to subtract.