Question

Calculate the drift current density ( current density due to conductivity) induced in a silicon semiconductor at T =300 K when the electron concentration is 1016 cm-3 and applied electric field is 30 V/cm.]

Answer 1

Drift Density = 64.8 A/cm²

Step-by-step explanation:

Drift Density is given as

Drift Density = σ x E, where V is the conductivity and E is the applied electric field

Jd = σ x E, equation 1

At 300 K, it is known that the electron mobility μ(n), is given equal to 1350 cm²/Vs

Therefore, conductivity (σ) is

σ = e x n x μ(n), where n is the electron concentration and e is the charge on each electron

Substitute 1.6 x 10⁻¹⁹ for e, 10¹⁶ for n and 1350 for μ(n)

σ = 1.6 x 10⁻¹⁹ x 10¹⁶ x 1350

σ = 2.160

Substitute the value of σ in equation 1

Then, the drift current density is:

Jd = sigma x E, where E is the applied electric field

Jd = 2.16 x 30

Jd = 64.8 A/cm²