Question

What is the equation for calculating ionized impurity concentration?

Answer 1

The equation for calculating the ionized impurity concentration in a semiconductor material is given by the equation:

$n_i^2=N_d{N}_a\exp \left(\frac{E_i}{kT}\right)$

where:

• $n_i$ is the intrinsic carrier concentration
• $N_d$ is the concentration of donor impurities (usually in the form of phosphorus, arsenic, or other elements that donate an extra electron to the material)
• $N_a$ is the concentration of acceptor impurities (usually in the form of boron, gallium, or other elements that create a "hole" in the material)
• $E_i$ is the intrinsic energy level (also known as the intrinsic Fermi level) in electron volts (eV)
• $k$ is Boltzmann's constant ($8.617333262145\times 10^{-5}$ eV/K)
• $T$ is the temperature in Kelvin (K)

This equation relates the impurity concentrations to