Georgian Scientists/ . 6  N 1, 2024 153

Georgian Scientists

Vol. 6  Issue 1, 2024

https://doi.org/10.52340/gs.2024.06.01.21

,1 ,2,3 ,4 1

1 ; 2

3 ; 4

B .
 (SixGe1-x, x=0.7, 0.72, 0.76, 0.8  0.83) 

. 

. , 
 SixGe1-x

.

: SixGe1-x , 
, .

. 
 ZT = S2 T/ ,  S, T, ,

, 
.

 ZT-
. 

(BE)  (B*)(1)  [1,2]. 
:



Georgian Scientists/ . 6 N 1, 2024 154

 B =6.668 10-2 Eg, (1)

U = (Tm /m ) /  ( m  - , m -
, Eg - ). B

 (U , , Eg), 
 ZT- .

 B*, BE  ZT
 (

, ). , 
(SixGe1-x, x=0.7, 0.72, 0.76, 0.8  0.83)  (300-306)oK

.  BE

.

 N- ;
 n=3.2 1026 -3 ;  

; 
 ( . .5 ); 

 [3]- Eg - x 
.1),  x- . Eg

3d10 .

.1. (a) Eg - x  [3], (b) m*/m0 - x  (c) Eg/k -
x .

.2- B  - x  ZT - x  SixGe1-x . 
ZT-  (~0.05-0.1) ,  SiGe 



Georgian Scientists/ . 6 N 1, 2024 155

:  ZT ~0.6-  P-
~0.8-  N- ,  940oC-  [4,5].

.2. B  - x (o)  ZT - x ( ) .

BE= S2/BS,

BS=S
( )

( ) +
[ ( )]

,  Sr -

: S=(qe/kB)S 1.16 104S (q  - , k  -
). [1]-  ZT-

 BET/k- .
.3- ,  SixGe1-x

.

.3. ZT - 300BE/k  SixGe1-x : x=0.7 (o), 0.72 ( ), 0.76 ( ), 0.8 ( ) 
0.83 ( ).

,  ZT-
. : 

.

.4-
. , .

ZT  - B  [2]-
.



Georgian Scientists/ . 6 N 1, 2024 156

.4. ZT- B .

 ( .5).

.5. (a) B - BE  (b) m*/m0 - B .  -  (2)-
.

:
B 1.544·104EgBE/k, , 

B (0.088x+0.238)·104BE (2) ( . (2)). 
, 

 SixGe1-x .

[6]:

1.059·10-15
/ ( ) .

/

( ) + ( )

6.608 10 15

T
[ne(Sr 2)]2/3. (3)

 (3) :
m*/m0 0.816(eSr-2)2/3 ( . .1b- m*/m0 - x ).



Georgian Scientists/ . 6 N 1, 2024 157

:

(1)  ( ) .

(2) Eg/k - x  ( .1c) , Eg/k 0.057x+0.154.

 (SixGe1-x, x=0.7, 0.72, 0.76, 0.8  0.83) B*, BE

 ZT .  Eg -  x, B  -  x,  ZT - x,  m*/m0 -  x,  BE - B  m*/m0 - B
.

1. X.Zhang, Z.Bu et al. Electronic quality factor for thermoelectrics. Science Advances, 2020, 6,
eabc0726.
2. W.Liu, J.Zhou et al. New insight into the material parameter B to understand the enhanced thermoelectric
performance of Mg2Sn1 yGexSby. Energy Environm. Sci., 2016, 9, 530-539.

 3. A.M.Al-sheikh, M.M.Hussien, S.J.Abdullah. Pressure and temperature dependence of energy gap in
SiC and Si1-xGex. Raf. Sci., 2019, 28, 53-61.

4. G.Bokuchava, K.Barbakhadze, I.Nakhutsrishvili. Thermoelectric parameters of alloy p-Si0.7Ge0.3. Bull.
Georg. Acad. Sci., 2023, 17, 33-37.
5. G.Bokuchava, K.Barbakadze, I.Nakhutsrishvili. On the thermoelectric alloy n-SixGe1-x. Material Sci.
& Engin., 2023, 7, 54-57.
6.  G.J.Snyder,  A.Pereyra,  R.Gurunathan.  Effective  mass  from  Seebeck  coefficient.  Adv.  Funct.
Materials. 2022, 32, 2112772.



Georgian Scientists/ . 6 N 1, 2024 158

Dependence of the Thermoelectric Characteristics of the Silicon-Germanium Alloy on
the Generalized Parameter of the Material and Electronic Quality Factor

Rafiel Tkhinvaleli,1 Zurab Adamia,2,3 Lasha Loria,2 Irakli Nakhutsrishvili1

1Institute of Cybernetics of Georgian Technical University; 2Sukhumi Institute of Physics and Technology;
3University of Georgia; 4Tbilisi State University

Summary

The generalized parameter B* of silicon-germanium alloy is discussed. The influence of the phase
composition of the material (SixGe1-x, x=0.7, 0.72, 0.76, 0.8 and 0.83) on the mentioned parameter under
conditions close to room temperature has been studied. The relationship between the electronic quality
factor and the generalized parameter is also constructed. A formula has been obtained
(B* (0.088x+0.238)·104BE) that directly relates the generalized material parameter to the electronic
correspondence coefficient for a given composition of SixGe1-x .

Keywords: SixGe1-x alloy, generalized parameter of thermoelectric material, electronic quality factor.