Prévia do material em texto
Step 1 of 4 3.004P Intrinsic concentration of silicon can be calculated as follows: Here, B is a material dependent parameter, E₈ is bandgap energy, k is Boltzmann's constant T is the temperature in Kelvin. Step 2 of 4 Substitute for B , 1.12eV for E₈ , 8.62x10⁻⁵ eV/K for k. 300K for T in equation (1). -1.12 Therefore, the intrinsic concentration of silicon is - Step 3 of 4 Silicon crystal doped with phosphorus, Hence, n-type semiconductor is formed. For a n-type semiconductor concentration of electrons is equal to the donor concentration. Form the Mass-action law, = = (2) Step 4 of 4 Consider the hole concentration drops below the intrinsic level by a factor of because of Si doped with Phosphorus. Thus, the hole concentration is, Substitute for and for P. in equation (2). Therefore, the concentration of ND is must be