Page 214 - Semiconductor For Micro- and Nanotechnology An Introduction For Engineers

Local Equilibrium Description
N
12
Absolute
qT N
11
Thermo- ε = – ---------------- (6.50)
electric is called the absolute thermoelectric power of a material. If we insert
Power
this into (6.41b) we obtain
N N 22 – N N 21
11
12
j Q = -------------------------------------------∇T (6.51)
N T
11
where the coefficient of the temperature gradient is called the thermal
conductivity
N N 22 – N N 21
11
12
Thermal κ = ------------------------------------------- (6.52)
N T
11
Conductivity
Let us go back to the case where there are two different materials A
and in a ring like structure as shown in Figure 6.5. The ring is open
B
A ε
A

T 1 T 2

ε
B B
Figure 6.5. Contact between two B a b
different materials showing See-
T 0
beck effect.

anywhere in the material B, where there is a temperature T . The
0
interfaces between the two different materials are kept at tempera-
a
tures T 1 and T 2 . We integrate (6.49) along a path from to b
s

Semiconductors for Micro and Nanosystem Technology 211