Doping

n=Nce(EcEF)kTn=N_c\cdot e^{\frac{-(E_c-E_F)}{kT}}p=Nve(EFEv)kTp=N_v\cdot e^{\frac{-(E_F-E_v)}{kT}}
  • EcE_c is the position of the conduction band minimum
  • EvE_v is the position of the valence band maxmimum
  • kk is Boltzmann’s constant
  • NxN_x are the effective density of states
np=ni2np=n_i^2
  • nin_i = Intrinsic carrier concentration
ni=NcNveEg2ktn_i=\sqrt{N_cN_v}e^{\frac{-E_g}{2kt}}
  • EgE_g = Band Gap = EcEvE_c-E_v

Substitutional Doping

  • Donated electrons are delocalised
  • Ions are immobile
Nc2[2πmnkTh2]3/2N_c \equiv 2 \left[ \frac{2\pi m_nkT}{h^2}\right]^{3/2}Nv2[2πmpkTh2]3/2N_v \equiv 2 \left[ \frac{2\pi m_pkT}{h^2}\right]^{3/2}