Band structure and carrier concentration of Indium Arsenide (InAs)

InAs - Indium Arsenide

Band structure and carrier concentration

Basic Parameters
Temperature Dependences
Dependence of the Energy Gap on Hydrostatic Pressure
Energy Gap Narrowing at High Doping Levels
Effective Masses
Donors and Acceptors

Basic Parameters

Energy gap 0.354 eV
Energy separation (EΓL) between Γ and L valleys 0.73 eV
Energy separation (EΓX) between Γ and X valleys 1.02 eV
Energy spin-orbital splitting 0.41 eV
Intrinsic carrier concentration 1·1015 cm-3
Intrinsic resistivity 0.16 Ω·cm
Effective conduction band density of states 8.7·1016 cm-3
Effective valence band density of states 6.6·1018 cm-3


Band structure and carrier concentration of InAs.
Important minima of the conduction band and maxima of the valence band.
Eg= 0.35 eV
EL= 1.08 eV
EX= 1.37 eV
Eso = 0.41 eV

Temperature Dependences

Temperature dependence of the direct energy gap

Eg = 0.415 - 2.76·10-4xT2/(T+83) (eV),
where T is temperature in degrees K (0 <T < 300).
(Fang et al. [1990]).

Effective density of states in the conduction band

Nc≈1.68·1013·T3/2 (cm-3).

Effective density of states in the valence band

Nv≈ 1.27·1015·T3/2(cm-3).
The temperature dependences of the intrinsic carrier concentration.
Fermi level versus temperature for different concentrations of shallow donors and acceptors.

Dependences on Hydrostatic Pressure

Eg≈Eg(0) + 4.8·10-3P (eV)
EL≈ EL(0) + 3.2·10-3P (eV)
where P is pressure in kbar (Edwards and Drickamer[1961]).

Energy Gap Narrowing at High Doping Levels

Energy gap narrowing versus donor (Curve 1) and acceptor (Curve 2 ) doping density.
Curves are calculated according (Jain et al. [1990]).
Points show experimental results for n-InAs (Semikolenova et al. [1978]).

For n-type InAs

ΔEg = 14.0·10-9·Nd1/3 + 1.97·10-7·Nd1/4 + 57.9·10-12·Nd1/2 (eV)
(Jain et al. [1990])

For p-type InAs

ΔEg = 8.34·10-9·Na1/3 + 2.91·10-7·Na1/4 + 4.53·10-12·Na1/2 (eV)
(Jain et al. [1990])

Effective Masses

Electrons:
Electron effective mass versus electron concentration
(Kesamanly et al. [1969]).
For Γ-valley mΓ = 0.023mo
Nonparabolicity:
E(1+αE) = h2k2/(2mΓ)
α = 1.4 (eV-1)
In the L-valley effective mass of density of states mL=0.29mo
In the X-valley effective mass of density of states mX=0.64mo
Holes:
Heavy
mh = 0.41mo
Light
mlp = 0.026mo
Split-off band
mso = 0.16mo
Effective mass of density of states mv = 0.41mo

Donors and Acceptors

Ionization energies of shallow donors

≥ 0.001(eV): Se, S, Te, Ge, Si, Sn, Cu

Ionization energies of shallow acceptors, eV

Sn Ge Si Cd Zn
0.01 0.014 0.02 0.015 0.01
(Guseva et al. [1974], [1975])