SiGe  Remarks  Referens  
Energy gaps, Eg_{indirect } (Δ conduction band min)  Si_{1x}Ge_{x}  1.120.41x + 0.008x^{2} eV  300 K, x < 0.85  
Si (x=0)  1.12 eV  300 K, x = 0.  see Si. Band structure  
Energy gaps, Eg_{indirect
} (L conduction band min)  Si_{1x}Ge_{x}  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 E_{Γ1}  Si_{1x}Ge_{x}  4175  (2814 ± 55)x meV  70 K; 0 < x < 0.3, Linear Fitting Si_{1x}Ge_{x} films on Si substrates  Ebner et al. (1998) 
Si (x=0)  3.4 eV  300 K  see Si. Band structure  
Ge (x=1)  0.8 eV  300 K  see Ge. Band structure  
E_{g}(ΓX)  Si_{1x}Ge_{x}  0.8941 + 0.0421x+ 0.1691x^{2}  calculated  Krishnamurti et al. (1983) 
E_{g}(ΓL)  Si_{1x}Ge_{x}  0.7596 + 1.0860x+ 0.3306x^{2}  calculated  Krishnamurti et al. (1983) 
Energy separation E_{Γ2}  Si_{1x}Ge_{x}  (3400 ± 7)  (300 ± 40)x meV  70 K; 0 < x < 0.3, Linear Fitting Si_{1x}Ge_{x} films on Si substrates  Ebner et al. (1998) 
Si (x=0)  4.2 eV  300 K  see Si. Band structure  
Ge (x=1)  3.2 eV  300 K  see Ge. Band structure  
 
Valence band  
Energy of spinorbital splitting E_{so}  Si_{1x}Ge_{x}  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  Si_{1x}Ge_{x}  ~ 2.8 x 10^{19}cm^{3}  300 K, x < 0.85  
Si_{1x}Ge_{x}  ~ 1.0 x 10^{19}cm^{3}  300 K, x > 0.85  
Si (x=0)  2.8 x 10^{19}cm^{3}  300 K, x = 0.  see Si. Band structure  
Ge (x=1)  1.0 x 10^{19}cm^{3}  300 K, x = 1.  see Ge. Band structure  
Effective valence band density of states  Si (x=0)  1.8 x 10^{19}cm^{3}  300 K, x = 0.  see Si. Band structure 
 Ge (x=1)  0.5 x 10^{19}cm^{3}  300 K, x = 1.  see Ge. Band structure 
 
Intrinsic carrier concentration  Si_{1x}Ge_{x}  see Si_{1x}Ge_{x}. Intrinsic carrier concentration  
Si (x=0)  1 x 10^{10} cm^{3}  300 K, x = 0.  see Si. Band structure  
Ge (x=1)  2 x 10^{13} cm^{3}  300 K, x = 1.  see Ge. Band structure  
Energy Gaps vs. Composition  
E_{1}  Si_{1x}Ge_{x}  3452  (1345 ± 25)x meV  70 K; 0 < x < 0.3, Linear Fitting Si_{1x}Ge_{x} films on Si substrates  Ebner et al. (1998) 
E'_{1}  Si_{1x}Ge_{x}  5402 ± 25 + (280 ± 120)x meV  
E_{2} (X)  Si_{1x}Ge_{x}  4351 ± 38 + (210 ± 180)x meV  
E_{2} (Σ)  Si_{1x}Ge_{x}  4518 ± 129 + (880 ± 600)x meV  
E_{g}(ΓX)  Si_{1x}Ge_{x}  0.8941 + 0.0421x+ 0.1691x^{2}  calculated  Krishnamurti et al. (1983) 
E_{g}(ΓL)  Si_{1x}Ge_{x}  0.7596 + 1.0860x+ 0.3306x^{2}  calculated  Krishnamurti et al. (1983) 
Band
structure of Si at 300 K.
 
Band
structures of Ge. see also

Si_{x}Ge_{1x}.
Indirect Energy gap vs. composition at 296 K Onephonone model of the absorption edge. At about x=0.15 a crossover occurs of the Gelike [111] conduction band minima and the Silike [100] conduction band minima Braunstein et al. (1958)  
Si_{1x}Ge_{x}.
Fundamental (indirect) band gap & excitonic band gap at 4.2 K Squares  band gap of Si_{1x}Ge_{x} at 4.2 K (absorption measurements) ; Dots  excitonic band gap of Si_{1x}Ge_{x} at 4.2 K (photoluminescence measurements) Braunstein et al. (1958) and Weber & Alonso (1989)  
Si_{1x}Ge_{x}.
Composition dependences of several important direct transitions observed. Kline et al. (1968) and Pickering et al. (1993)  
Si_{1x}Ge_{x
} alloys.Fundamental indirect band gap vs. x of pseudomorphic Si_{1x}Ge_{x}
(001) alloys: (a) on Si substrate; (b) on Si_{0.5}Ge_{0.5} substrate; (c) on Ge substrate. Dashed lines  unstrained bulk band gap. Experimental points are taken from Lang et al. (1985) and Dutartre et al. (1991). Solid lines  calculated curves. People (1985, 1986) and Van de Walle & Martin (1986). 
0 < x < 0.3  Remarks  Referens  
E_{Γ1}  = 4175  (2814 ± 55)x  meV  70
K; Si_{1x}Ge_{x} films on Si substrates  Ebner et al. (1998) 
E_{Γ2}  = (3400 ± 7)  (300 ± 40)x  meV  
E_{1}  = 3452  (1345 ± 25)x  meV  
E'_{1}  = 5402 ± 25 + (280 ± 120)x  meV  
E_{2} (X)  = 4351 ± 38 + (210 ± 180)x;  meV  
E_{2} (Σ)  = 4518 ± 129 + (880 ± 600)x  meV 
Si_{1x}Ge_{x}  Compositional dependence of band gaps  Remarks  Referens  
E_{g}(ΓX)  = 0.8941 + 0.0421x+ 0.1691x^{2}  calculated  Krishnamurti et al. (1983)  
E_{g}(ΓL)  = 0.7596 + 1.0860x+ 0.3306x^{2} 
x=0 (Si)  E_{g} = 1.17 4.73 x 10^{4} x T^{2}/(T + 636)  (eV)  see also Si. Band structure and carrier concentration 
x=1 (Ge)  E_{g} = 0.742 4.8x 10^{4}·T^{2}/(T+235)  (eV)  see also Ge. Band structure and carrier concentration 
x=0 (Si)  E_{Γ2} = 4.34  3.91·10^{4}·T^{2}/(T+125)  (eV)  see also Si. Band structure and carrier concentration 
x=1 (Ge)  E_{Γ}_{1} = 0.89  5.82·10^{4}·T^{2}/(T+296)  (eV)  see also Ge. Band structure and carrier concentration 
Si_{1x}Ge_{x
} alloys. Fundamental indirect band gaps vs. temperature at different
x. Braunstein et al.(1958) 
Si_{1x}Ge_{x } alloys. Intrinsic carrier concentration vs.
temperature at different x. 
N_{c}
4.82 x 10^{15} · M ·
(m_{c}/m_{0})^{3/2·}T^{3/2}
(cm^{3}) 4.82 x 10^{15} (m_{cd}/m_{0})^{3/2
·} T^{3/2} 5.3 ^{ ·}
10^{15} x T^{3/2 }(cm^{3}) ,
where M=6
is the number of equivalent valleys in the conduction band.
m_{c} = 0.32m_{0} is the effective mass of the density
of states in one valley of conduction band.
m_{cd}
= 1.06m_{0} is the effective mass of density of states.
N_{c} 4.82 x 10^{15}
· M · (m_{c}/m_{0})^{3/2·}T^{3/2}
(cm^{3}) 4.82 x 10^{15} (m_{cd}/m_{0})^{3/2
}· T^{3/2} 2 ^{ ·}
10^{15} x T^{3/2} (cm^{3}) ,
where M
= 4 is the number of equivalent valleys in the conduction band.
m_{c} = 0.22m_{0} is the effective mass of the density
of states in one valley of conduction band.
m_{cd}
= 0.55m_{0} is the effective mass of density of states.
x=0 (Si)  N_{c} 4.82·10^{15}
^{ ·} (m_{v}/m_{0})^{3/2}·T^{3/2}
3.5·10^{15}·T^{3/2}
(cm^{3}), m_{v} = 0.81m_{0} is the hole effective mass of the density of states.  see also Si. Band structure and carrier concentration 
x=1 (Ge)  N_{c}
4.82·10^{15} ^{ ·} (m_{v}/m_{0})^{3/2}·T^{3/2}
9.6·10^{14}·T^{3/2}
(cm^{3}), m_{v} = 0.34m_{0} is the hole effective mass of the density of states.  see also Ge. Band structure and carrier concentration 
x=0 (Si)  E_{g}=E_{g}(0)1.4·10^{3}P  (eV)  see also Si. Band structure and carrier concentration 
x=1 (Ge)  E_{g} = E_{g}(0) + 5.1·10^{3}P  (eV)  see also Ge. Band structure and carrier concentration 
(&Teta;_{d} + 1/3&Teta;_{u}
 a) (for A valley)  (&Teta;_{d}
+ 1/3&Teta;_{u}  a) (for L valley)  b  &Teta;_{u}  &Teta;_{u}  Remarks  Referens  
Si  1.72 eV  3.12 eV  2.35 eV  9.16 eV  16.14 eV  Theory  Van de Walle & Martin (1986) 
1.5 ±0.3 eV  2.10 ±0.1 eV  4.85 ±0.15 eV  Experiment  Laude
et al. (1971), Chandrasekar & Pollak (1977), Balslev (1966)  
Ge  1.31 eV  2.78 eV  2.55 eV  9.42 eV  15.13 eV  Theory  Van de Walle & Martin (1986) 
2.0 ± 0.5 eV  2.86 ±0.15 eV  16.2 ± 0.4 eV  Experiment  Laude et al. (1971), Chandrasekar & Pollak (1977), Balslev (1966) 
Both the valence and conduction band degeneracy are lifted by the uniaxial [001] strain component, which leads to the following splittings (Van de Walle and Martin, (1986)):
For higher Ge contents, the conduction band becomes Gelike with electrons being located at the L minimum. With the uniaxial strain component being directed along [001], no splitting of the L minimum occurs for reasons of symmetry.
Si_{1x}Ge_{x}.
Schematic diagram of the relevant band edges of Si subjected to hydrostatic
and uniaxial strain as described in equations. Energy values apply to a tensely strained Si quantum well on an Si_{1x}Ge_{x} substrate with x = 30% Schaffler(1997)  
Si_{1x}Ge_{x}.
Contour plots of the conduction ΔE_{c} and valence ΔE_{v}
band offsets of pseudomorphic Si_{1x}Ge_{x} layers on cubic Si_{1xs}Ge_{xs}
substrates over the complete range of x and xs. The signs correspond to an electronic energy scale, where the active layer (x) is referred to the cubic substrate of composition xs. Excitoncorrected experimental results indicate that for x > xs and x < 0.8, the conduction band offset is 0<ΔE_{c}<+40 meV [Penn et al. (1999)]; that is, for most of the (x,xs) combinations the band alignment is staggered (Type II) with the valence band offset being always in favor of the material with the higher Ge content. The theoretically predicted Type I region for x and xs being larger than about 80% has not been confirmed experimentally Schaffler(1997)  
Si_{1x}Ge_{x}.
Solid lines  Variation of the relevant band edges of a strained Si layer on a cubic Si_{1xs}Ge_{xs} substrate . The dashed lines correspond to the substrate bands. LH, light holes; HH, heavy holes; SO, spinorbit split holes Schaffler(1997)  
Si_{1x}Ge_{x}.
Solid lines  Variation of the relevant band edges of a strained Ge
layer on a cubic Si_{1xs}Ge_{xs} substrate . The dashed lines correspond to the substrate bands. . LH, light holes; HH, heavy holes; SO, spinorbit split holes Schaffler(1997) 
At x < 0.85, Si_{1x}Ge_{x} alloys are considered as "Silike" material:  Remarks  Referens  
Effective electron mass (longitudinal)m_{l}  0.92m_{o}  Schaffler F.(2001)  
Effective electron mass (transverse)m_{t}  0.19m_{o}  Schaffler F.(2001)  
Effective mass of density of states
m_{cd}=M^{2/3} m_{c} (for all valleys of conduction band)  1.06m_{o}  Son
et al. (1994); Son et al. (1995)  
Effective mass of the density of states m_{c}=(m_{l}+m_{t2})^{1/3} (in one valley of conduction band)  0.32m_{o}  
Effective mass of conductivity m_{cc}= 3/(1/m_{l}+2/m_{t})  0.26m_{o} 
At 0.85< x <1, Si_{1x}Ge_{x} alloys are considered as "Silike" material:  Remarks  Referens  
Effective
electron mass (longitudinal)m_{l}  0.159m_{o}  Schaffler F.(2001)  
Effective electron mass (transverse)m_{t}  0.08m_{o}  Schaffler F.(2001)  
Effective mass of density of states
m_{cd}=M^{2/3} m_{c} (for all valleys of conduction band)  1.55m_{o}  Son
et al. (1994); Son et al. (1995)  
Effective mass of the density of states m_{c}=(m_{l}+m_{t2})^{1/3} (in one valley of conduction band)  0.22m_{o}  
Effective mass of conductivity m_{cc}= 3/(1/m_{l}+2/m_{t})  0.12m_{o} 
Si_{1x}Ge_{x}.
Variation of the conduction band effective masses vs. composition Rieger and Vogl (1993) 
Remarks  Referens  
Effective hole masses (heavy) m_{hh}  Si (x=0)  0.537 m_{o}  4.2 K  see also Si. Effective Masses 
Ge (x=1)  0.33 m_{o}  see also Ge. Effective Masses  
Effective hole masses (light) m_{lh}  Si (x=0)  0.153 m_{o}  see also Si. Effective Masses  
Ge (x=1)  0.0430 m_{o}  see also Ge. Effective Masses  
Effective hole masses (spinorbitsplit ) m_{so}  Si_{1x}Ge_{x}  (0.230.135x) m_{o}  300 K  Schaffler F.(2001) 
Si (x=0)  0.234 m_{o}  see also Si. Effective Masses  
Ge (x=1)  0.095(7) m_{o}  30 K  see also Ge. Effective Masses 
Si_{1x}Ge_{x}.
Valence band dispersion along [100] and [110] for Si_{0.5}Ge_{0.5}
on Si(001). (schematic view) Schaffler F.(2001)  
Si_{1x}Ge_{x}.
Valence band parameters A, B, and C vs. composition x Schaffler F.(1997)  
Si_{1x}Ge_{x}.
Heavy hole effective mass density of states m_{hd} vs. energy at different
x . Manku & Nathan (1991)  
Si_{1x}Ge_{x}.
Light hole effective mass density of states m_{hl} vs. energy at different
x . Manku & Nathan (1991)  
Si_{1x}Ge_{x}.
Experimental heavy hole cyclotron masses in strained Si_{1x}Ge_{x}
quantum wells. Dots  Cheng et al. (1994), squares  Wong et al. (1995). Dashed line corresponds to unstrained bulk, Bottom solid line is a prediction for strained Si_{1x}Ge_{x} 