In the ion conduction type conductor, the carrier may be positive ion or negative ion. In the electronic conduction type conductor, carrier is electron and current can be formed by electron movement. With the increasing of carrier concentration, thermoelectric coefficient α will reduce and thermal conductivity σ will increase. In the thermal coefficientλ, the lattice thermal conductivity λ
P (about 90%) is irrelevant to the carrier concentration, while the electron thermal conductivity λ
e is proportional to the carrier concentration. So the appropriate carrier concentration n is selected to make
get the maximum difference. Figure of merit z and other three parameters α, ρ, λ have a certain relationship with carrier concentration n. When n is close to 10
19cm
-3, the value of Z can be the maximum.
Though controlling the carrier concentration n, thermal conductivity σ and thermoelectric coefficient α can be improved and thermal conductivity λ
e can be reduced. So the current investigators of
TEC materials should try to reduce thermal conductivity λ
p. One of the effective ways to reduce the lattice thermal conductivity is to increase phonon scattering factors, but grain boundary structure, grain boundary content and the interaction of the grain boundary and the phonon need to be further studied.
If you have any questions and suggestions about thermoelectric cooler, please feel free to contact us.We will be very happy to receive your feedback.
Our web site is
http://www.analogtechnologies.com/
