Band structure and carrier concentration of Gallium Antimonide (GaSb)

Band structure and carrier concentration
Basic ParametersTemperature 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 | 0.726 eV |
Energy separation (EΓL) between Γ and L valleys | 0.084 eV |
Energy separation (EΓX) between Γ and X valleys | 0.31 eV |
Energy spin-orbital splitting | 0.80 eV |
Intrinsic carrier concentration | 1.5·1012 cm-3 |
Intrinsic resistivity | 103 Ω·cm |
Effective conduction band density of states | 2.1·1017 cm-3 |
Effective valence band density of states | 1.8·1019 cm-3 |
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Band structure and carrier concentration of GaSb. 300 K Eg= 0.726 eV EL = 0.81 eV EX = 1.03 eV Eso = 0.8 eV |
Temperature Dependences
Temperature dependence of the energy gap
(Wu and Chen [1992])
Eg = 0.813 - 3.78·10-4·T2/(T+94) (eV),where T is temperature in degrees K (0 < T < 300).
Temperature dependence of energy EL
EL = 0.902 - 3.97·10-4·T2/(T+94) (eV)Temperature dependence of energy EX
(Lee and Woolley [1981])
EX = 1.142 - 4.75·10-4·T2/(T+94) (eV)
Effective density of states in the conduction band
Nc = 4.0·1013·T3/2 (cm-3)Effective density of states in the conduction band
Nc = 4.0·1013·T3/2 (cm-3)Effective density of states in the valence band
Nv = 3.5·1015·T3/2 (cm-3)![]() |
The temperature dependences of the intrinsic carrier concentration. |
Dependences on Hydrostatic Pressure
Eg = Eg(0) + 14.5·10-3P (eV)EL = EL(0) + 5.0·10-3P (eV)
EX = EX(0) - 1.5·10-3P (eV),
where P is pressure in kbar.
Energy Gap Narrowing at High Doping Levels
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Energy gap narrowing versus acceptor acceptor doping density. Curve is calculated for p-GaSb according to Jain et al. [1990]. Points show experimental results (Titkov et al. [1981]). |
For n-type GaSb
(Jain et al. [1990]):
Eg = 13.6·10-9·Nd1/3 +
1.66·10-7·Nd1/4 +
119·10-12·Nd1/2 (eV)
For p-type GaSb
(Jain et al. [1990]):
Eg = 8.07·10-9·Na1/3 +
2.80·10-7·Na1/4+
4.12·10-12·Na1/2 (eV)
Effective Masses
Electrons:
For Γ-valley | mΓ = 0.041mo |
In the L- valley the surfaces of equal energy are ellipsoids | |
ml= 0.95mo | |
mt= 0.11mo | |
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mL= 16(mlmt2)1/3= 0.57mo | |
In the X- valley the surfaces of equal energy are ellipsoids | |
ml= 1.51mo | |
mt= 0.22mo | |
|
|
mX= 9(mlmt2)1/3= 0.87mo |
Holes:
Heavy |
mh = 0.4mo |
Light |
mlp = 0.05mo |
|
mso = 0.14mo |
Effective mass of density of states | mv = 0.8mo |
Effective mass of density of conductivity (Heller and Hamerly [1985]) |
mvc = 0.3mo |
Donors and Acceptors
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The diagram of IV group donor states (Vul' et al. [1970]). |
Ionization energies of shallow donors (eV)
Te(L) | Te(X) | Se(L) | Se(X) | S(L) | S(X) |
~0.02 | ≤0.08 | ~0.05 | ~0.23 | ~0.15 | ~0.30 |
Ionization energies of shallow acceptors (eV):
The dominant acceptor of undoped GaSb seems to be a native defect.This acceptor is doubly ionizable
Ea1 | Ea2 | Si | Ge | Zn |
0.03 | 0.1 | ~0.01 | ~0.009 | ~0.037 |