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 will reduce and thermal conductivity will increase. In the thermal coefficient, the lattice thermal conductivity P (about 90%) is irrelevant to the carrier concentration, while the electron thermal conductivity e is proportiona...(more)
Although thermoelectric cooling technology has been developed very fast, there are still many problems that need resolution. Because of the material constraints, the cooling capacity of thermoelectric cooler (TEC) is limited and its cooling efficiency is too low. With the increase of the required temperature difference, the more the TEC series is, the lower the cooling efficiency is. So TEC cannot completely replace the traditional cooling technology, which can only be used in the small cooling...(more)
Until 1950s, with the rapid development of semiconductor thermoelectric mateials with good performances, the efficiency of thermoelectric effect was improved so greatly that the thermoelectric refrigeration and the thermoelectric generation entered into the field of engineering practice. When comparing with the existing compression refrigeration or absorption refrigeration, the thermoelectric cooler ( TEC ) depends on the heat transfered by electrons to achieve refrigeration. It has the followin...(more)
Based on the thermoelectric effect, a thermoelectric generator (TEG) converts heat directly into electricity. Because of no moving parts, it is very silent and highly reliable. 1 The classification of TEG According to the hot end temperature of TEG , it can be divided into three categories: high temperature TEG (more than 700℃), medium temperature TEG (between 400 and 700℃) and low temperature TEG (under 400℃). According to the usage heat source, there are four types of TEG: 1) radio isotop...(more)
Thermoelectric cooler is like a heat pump when its working, transferring heat from one point to another. This is not a common heat absorption process or a magic heat consumption process. When its powered on, one end of the TEC module will become cold while the other end hot. The cooled down end transfers the heat to the hot end, which conforms to the thermodynamics law. In order to complete a heat transfer process, the thermoelectric cooler needs to be connected to a proper heat sink, which is u...(more)
The material figure of merit Z is an important parameter to measure the cooling capacity of TEC and its expression is . In order to improve Z value, conductivity and Seebeck coefficient should be improved and thermal conductivity should be reduced. consists of phonon thermal conductivity p (about 90%) and electronic conductivity e. These three parameters are not independent of each other, which all are the function of carrier concentration n and temperature T. In the condition of different envir...(more)
Low dimensional thermoelectric (0~3D) material is a new research in recent years. Because of the function of the quantum well and quantum wire, low dimensional material has extraordinary thermoelectric property. The low dimension can increase and phonon boundary scattering of the potential well surface. Terry M Tritt obtained the different dimension curve of Bi 2 Te 3 with the change of quantum welldW(quantum wire thickness). The result shows that three dimensional material do not change with th...(more)
3 Thermoelectric materials In the view of the research and development of thermoelectric materials, lead telluride is used as a thermoelectric material in the early days, and then TAGS alloy is developed for P-type element (N-type is still PbTe). The temperature of the hot end can be up to 600℃. After using new thermoelectric materials in hundred watt thermoelectric generator and universal thermoelectric generator, the hot end temperature can reach 1000℃ and its mechanical properties and oxid...(more)
