Contents of Journal of Thermoelectricity, No.3, 1996

A.I.Kasiyan. Thermoelectric Properties of Organic Semiconductors

The thermoelectric efficiencies of some organic semiconductors are analyzed. It is stated that the values of efficiency are much smaller than the values obtained for the most efficient inorganic materials. The model of quasi-one-dimensional crystal with high thermoelectric efficiency is proposed and discussed.

S.V.Melnichuk, S.V.Kosyachenko. Thermoelectric Properties of Superlattices (Review)

The figure of merit for superlattice composite can be increased to values above those for either of the bulk systems because of the two-dimensional electronic properties of thin layers.

G.A.Ivanov. Grade Thermoelectric Coolers

Thermoelectric coolers composed of unequally high thermoelements forming grades and having the only heat transfers to a radiator. Thermal relation with working cold junctions of the grades is realized at the expense of transverse thermal conduction of elements joined by thermal conductive adhesive and a thermal conductive and current nonconductive array. It has been demonstrated experimentally the practical equality of grade and cascade thermoelectric coolers (GTEC and CTEC) by temperature decrease with some advantage of GTEC in power consumption connected with absence od internal thermal transfers available in CTEC. Isothermal surfaces lying on the grade cold junctions are taken as being close to planes parallel to a radiator plane, and applying the heat balance equation for the extended parts of thermoelement grades formulas, for temperature difference across the grades have been derived. Equating the parameters for the TE extended parts and TE corresponding parts cut by the isothermal planes, it were derived simple estimating formulas for temperature differences across grades that are in satisfactory agreement with experiment.

P.I.Baransky. Diagnostics of Multi-valley Semiconductors Perfection by Thermo-emf Anisotropy of Electrons Drag by Phonons (Gigantic thermo-emf Anisotropy of Drag in Multi-Valley Semiconductors and Metrology)

1. Physical causes for gigantic anisotropy of thermo-emf generation in elastic and directionally deformed multi-valley semiconductors over electron-phonon drag.
2. On the methods of mobility anisotropy parameter K and thermo-emf anisotropy of drag parameter measurement in elastic and directionally deformed multi-valley n-type crystals of Ge and Si.
3. Comparison of the experimental data on anisotropy of mobility and on the thermo-emf anisotropy parameter of drag obtained over the experiments with n-Si crystals doped by phosphorus impurity through melt and by the nuclear transmutation method (that is, obtained during the experiments with ordinary and transmutationally doped crystals).
4. Pecularities of phonon-phonon relaxation in multi-valley semiconductors (n-Si type) and physical interpretation of the obtained results.
5. Conclusions.

Yu.Is.Ravich. Exceptional Thermoelectric Properties of Cluster Superlattices Based in Opal

Cluster superlattices are referred to a new type of materials having structures similar to crystals but with a structural unit increased to a submicron size. Metal or semiconductor clusters are introduced into opal lattice voids. Two types cluster systems have been considered: with thermionic current through small gaps between clusters and with tunnelling through intercluaster barriers. The first type system is considered as regular three-dimensional lattice of thermionic converters. Experimentally measured thermo-emf of the GaAs clusters lattice accords well with calculated one. Thermoelectric figure of merit has been analyzed. Peculiarities of the volt-ampere characteristic of tunnel contacts lattice have been considered.

Yasutada Kibayashi, Kin-ichi Uemura. Robot Assembling of Micro-Thermomodules in Japan

This paper gives an outline of the automated assembling of micro- thermomodules using robot, in Japan. Micro-thermomodule mentioned here indicates a small size (outside dimensions: about 100 mm²) bismuth telluride thermomodule widely used for stabilizing the temperature of semiconductor laser diode for fiberoptic communications.

K.Matsuura. Waste Heat Recovery Thermoelectric Generation for the Production of Hydrogen Gas

Low voltage, high d.c. current output of a thermoelectric generator (TEG) provides an ideal source of electric power for the electrolysis of water to produce hydrogen. These considerations have resulted in the design and the construction of a prototype laboratory scale solid polymer electrolyte (SPE) electrolysis plant combined with a 100 W(e) TEG powered by low grade waste heat. The system has been evaluated at Osaka University and the results are given in this paper.

N.D.Marchuk. Creation of Thermoelectric Energy Systems of Increased Power on the Basis of Nuclear Reactor

The possibility of creation of so-called "built-in" NR-TEG power system has been considered. The complex of theoretical and experimental investigations of nuclear irradiation influence (thermal and fast nuclear reactor neutrons and modeling space irradiation including) on its physical properties has been performed to meet the resource requirements in the severe conditions of the outer space and nuclear reactor irradiation. The methods of prediction and improvement materials radiation stability have been elaborated. The method of "in-pile" material parameters regeneration has been also experimentally verified. From the effectiveness point of view the optimal "built-in" NR-TEG power range is from 50 to 500 kWe.