Dimensionless figure of merit

The n- and p-type semiconductor thermoelements comprising a TE couple typically have similar physical constants and their geometries are matched to minimize heat absorption. The dimensionless figure of merit of the couple is given by ... 

However, the figure of merit presented in Eq. (78) is not useful in characterizing third-order nonlinear materials because it is not dimensionless and it does not separate between linear and nonlinear absorption. More appropriate dimensionless figures of merit have been proposed by Stegeman [55, 56],... 

Figure 3 Dimensionless Figure of Merit Calculated for n-type Bi2Tes...

The performance of TE materials is characterized by a dimensionless figure of merit ZT = S oT/k (S, a, k, and T are the Seebeck coefficient, electrical conductivity, thermal conductivity, and absolute temperature. 

A highest dimensionless figure of merit ZT of 1.95x10 is obtained for PANI/GNs composite at 453 K, which is about 70 times higher than that of pure PANI [13]. 

Thermo-electric properties of conductive polymer nanofibers can be interesting for energy generation. In this case, a temperature gradient across a material is exploited to generate electricity (Seebeck effect). To this aim, one of the most important performance parameters is the dimensionless figure of merit ... 

The performance of thermoelectric material itself is quantified by a dimensionless figure of merit, ZT, which is defined as... 

Fig. 3.3 Temperature dependences of Seebeck coefficient S (a), electrical conductivity a (b), thermal conductivity k (c), and dimensionless figure of merit ZT (d). A pronounced peak in the Seebeck coefficient with two changes in the sign of the value was observed. This feature is consistent with the substantial entropy component found during DSC. A rapid increase of ZT value with the increasing temperature was observed, which reached 1.5 around 700 K...

ZT Y r A A A A A AC dimensionless thermoelectric figure of merit electronic coefficient of heat capacity (1+ZT)F2 crystal field singlet non-Kramers doublet (crystal field state) crystal field triplet crystal field triplet hybridization gap jump in heat capacity at Tc K KL -min P 6>d X JCO total thermal conductivity of solid thermal conductivity of electrons or holes thermal conductivity of lattice minimum lattice thermal conductivity electrical resistivity Debye temperature magnetic susceptibility magnetic susceptibility at T = 0... 

Figure 3. Grain size dependence of dimensionless thermoelectric figure of merit, ZT, for (a) SiGe and (b) PbTe...

The n-type PbTe as a thermoelctric material whose carrier concentration n is controlled to have around 3.0 x 10 m is commonly used in the temperature range of a hot side electrodes between 600 and 950 K.[l] The thermoelectric figure of merit Z has a maximum value of 1.4 X 10 K at 700 K and the dimensionless thermoelectric figure of merit ZT attains to almost unity. Then, PbTe and its solid solutions are utilized such as a solar thermoelectric generator (STG) and a radioisotope thermoelectric generator (RTG).[1,2]... 

Where a o is referred to as the electrical power factor, with a, the Seebeck coefficient, a the electrical conductivity and X. is the total thermal conductivity. The figure-of-merit is often expressed in its dimensionless form ZT wWe T is absolute tenperature. 

ZT dimensionless diermoelectric figure of merit K total thermal conductivity of solid... 

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