NSM Archive - Silicon Germanium (SiGe) - Band structure

SiGe - Silicon Germanium

Band structure and carrier concentration

Basic Parameters
Band structure
Intrinsic carrier concentration
Effective Density of States in the Conduction and Valence Band
Temperature Dependences
Dependences on Hydrostatic Pressure
Strain-Dependent Band Discontinuity
Effective Masses and Density of States
Dislocation Glide

Basic Parameters

SiGe  RemarksReferens
Energy gaps, Egindirect
      (Δ conduction band min)
Si1-xGex 1.12-0.41x + 0.008x2 eV 300 K, x < 0.85 
  Si (x=0)   1.12 eV 300 K, x = 0.see Si. Band structure
 
Energy gaps, Egindirect
      (L conduction band min)
Si1-xGex 1.86 - 1.2x eV 300 K, x > 0.85 
  Ge (x=1)   0.66 eV 300 K, x = 1.see Ge. Band structure

Conduction band     
Energy separation   EΓ1 Si1-xGex  4175 - (2814 ± 55)x meV70 K; 0 < x < 0.3, Linear Fitting
Si1-xGex films on Si substrates
Ebner et al. (1998)
  Si (x=0)   3.4 eV 300 Ksee Si. Band structure
 Ge (x=1)  0.8 eV 300 Ksee Ge. Band structure
Eg(Γ-X)Si1-xGex  0.8941 + 0.0421x+ 0.1691x2calculatedKrishnamurti et al. (1983)
Eg(Γ-L)Si1-xGex  0.7596 + 1.0860x+ 0.3306x2calculatedKrishnamurti et al. (1983)
Energy separation EΓ2 Si1-xGex  (3400 ± 7) - (300 ± 40)x meV70 K; 0 < x < 0.3, Linear Fitting
Si1-xGex films on Si substrates
Ebner et al. (1998)
  Si (x=0)   4.2 eV 300 Ksee Si. Band structure
 Ge (x=1)  3.2 eV 300 Ksee Ge. Band structure

Valence band     
Energy of spin-orbital splitting Eso Si1-xGex 0.044 + 0.246x eV 300 K 
  Si (x=0)   0.044 eV 300 K, x = 0.see Si. Band structure
 Ge (x=1)   0.29 eV 300 K, x = 1.see Ge. Band structure
     

Effective conduction band density of states

Si1-xGex ~ 2.8 x 1019cm-3300 K, x < 0.85 
  Si1-xGex ~ 1.0 x 1019cm-3300 K, x > 0.85 
  Si (x=0)   2.8 x 1019cm-3300 K, x = 0.see Si. Band structure
 Ge (x=1)   1.0 x 1019cm-3300 K, x = 1.see Ge. Band structure
     
Effective valence band density of states Si (x=0) 1.8 x 1019cm-3300 K, x = 0.see Si. Band structure

 

Ge (x=1)   0.5 x 1019cm-3300 K, x = 1.see Ge. Band structure

Intrinsic carrier concentration Si1-xGex   see Si1-xGex. Intrinsic carrier concentration
  Si (x=0)  1 x 1010 cm-3300 K, x = 0.see Si. Band structure
 Ge (x=1)  2 x 1013 cm-3300 K, x = 1.see Ge. Band structure
 
Energy Gaps vs. Composition     
E1 Si1-xGex  3452 - (1345 ± 25)x meV70 K; 0 < x < 0.3,
Linear Fitting
Si1-xGex films on Si substrates
Ebner et al. (1998)
E'1 Si1-xGex  5402 ± 25 + (280 ± 120)x meV
E2 (X)Si1-xGex  4351 ± 38 + (210 ± 180)x meV
E2 (Σ)Si1-xGex 4518 ± 129 + (880 ± 600)x meV
Eg(Γ-X)Si1-xGex  0.8941 + 0.0421x+ 0.1691x2calculatedKrishnamurti et al. (1983)
Eg(Γ-L)Si1-xGex  0.7596 + 1.0860x+ 0.3306x2calculatedKrishnamurti et al. (1983)


Band structure

Compositional dependence of band gaps (calculated):