Abstract: A thermoelectric (TE) device includes a first leg of TE material (a pseudobinary or pseudoternary alloy) and a second leg comprising a metal wire. The second leg is in thermal and electrical communication with the first leg. The TE device has a ZT value of approximately 2.0 at a temperature of approximately 300K.

Abstract: A solid-state energy converter with a semiconductor or semiconductor-metal implementation is provided for conversion of thermal energy to electric energy, or electric energy to refrigeration. In n-type heat-to-electricity embodiments, a highly doped n* emitter region made of a metal or semiconductor injects carriers into an n-type gap region. A p-type layer is positioned between the emitter region and gap region, allowing for discontinuity of corresponding Fermi-levels and forming a potential barrier to sort electrons by energy. Additional p-type layers can optionally be formed on the collector side of the converter. One type of these layers with higher carrier concentration (p*) serves as a blocking layer at the cold side of the converter, and another layer (p**) with carrier concentration close to the gap reduces a thermoelectric back flow component. Ohmic contacts on both sides of the device close the electrical circuit through an external load to convert heat to electricity.

Abstract: Thermoelectric material is produced through a process sequence including a liquid quenching, a primary solidification such as a hot pressing or extrusion and an upset forging; although the C-planes of the crystal grains are directed in parallel to the direction in which the force is exerted on flakes during the hot pressing/extrusion, the a-axes are randomly directed; the a-axes are oriented in a predetermined direction through the upset forging; this results in improvement of electric resistivity without reduction in the figure of merit.

Abstract: A thermoelectric conversion material is formed of a polycrystal structure of crystal grains composed of a silicon-rich phase, and an added element-rich phase in which at least one type of added element is deposited at the grain boundary thereof, the result of which is an extremely large Seebeck coefficient and low thermal conductivity, allowing the thermoelectric conversion rate to be raised dramatically, and affording a silicon-based thermoelectric conversion material composed chiefly of silicon, which is an abundant resource, and which causes extremely low environmental pollution.

Abstract: Disclosed is a foil segment for a thermoelectric generator comprising a top plate disposed in spaced relation above a bottom plate. An array of the foil segments is perpendicularly disposed in side-by-side arrangement between and in thermal contact with the bottom and top plates. Each foil segment comprises a substrate having a thickness of about 7.5-50 microns, opposing front and back substrate surfaces and a series of spaced alternating n-type and p-type thermoelectric legs disposed in parallel arrangement on the front substrate surface. Each of the n-type and p-type legs is formed of a bismuth telluride-based thermoelectric material having a thickness of about 5-100 microns, a width of about 10-100 microns and a length of about 100-500 microns. The alternating n-type and p-type thermoelectric legs are electrically connected in series and thermally connected in parallel such that a temperature differential between the bottom and top plates results in the generation of power.

Abstract: Tunneling-effect converters of thermal energy to electricity with an emitter and a collector separated from each other by a distance that is comparable to atomic dimensions and where tunneling effect plays an important role in the charge movement from the emitter to the collector across the gap separating such emitter and collector. At least one of the emitter and collector structures includes a flexible structure. Tunneling-effect converters include devices that convert thermal energy to electrical energy and devices that provide refrigeration when electric power is supplied to such devices.

Abstract: A thermoelectrically active p- or n-conductive semiconductor material is constituted by a ternary compound of the general formula (I)

Abstract: A thermoelectric nanogranular material with an enhanced Seebeck coefficient is provided. The thermoelectric nanogranular material includes particles having a grain size d. The grain size d is characterized by the relationship mfp/2<d<5mfp, where mfp is the phonon-limited mean free path of an equivalent bulk thermoelectric material prior to processing the bulk thermoelectric material into the thermoelectric nanogranular material having a grain size d. A method of making a thermoelectric nanogranular material is also provided. The method includes preparing a bulk thermoelectric material, reducing the bulk thermoelectric material into a powder, and filtering the powder to retain only those particles having a grain size d. The method also includes pressing the retained particles at a predetermined pressure and sintering the pressed particles at a predetermined temperature for a predetermined period of time in a predetermined atmosphere.

Abstract: The present invention provides the novel thermoelectric materials having, in combination, processability and excellent thermoelectric characteristics, the thermoelectric materials being able to provide n-type thermoelectric characteristics in accordance with the nature of the employed inorganic thermoelectric materials; a thermoelectric device employing the materials; and a method for producing the thermoelectric materials.

Abstract: A thermoelectric microactuator on a substrate includes a first temperature control element having a first surface bonded to the substrate and having a second surface. A first electrically nonconductive layer has a first surface bonded to the second surface of the first temperature control element and has a second surface. An actuator arm includes a first region bonded to the second surface of the first nonconductive layer and includes a flexure contiguously extending from the first region to an end cantilevered beyond the first nonconductive layer and forming an axis at the junction of the flexure and the first region. The first temperature control element controls the temperature of the actuator arm to thereby deflect the flexure about the axis.

Abstract: A thermoelectric (TE) device includes a first leg of TE material (a pseudobinary or pseudoternary alloy) and a second leg comprising a metal wire. The second leg is in thermal and electrical communication with the first leg. The TE device has a ZT value of approximately 2.0 at a temperature of approximately 300K.

Abstract: Thermoelectric material of (Bi, Sb)(Te, Se) system is produced through a liquid quenching method and an extrusion from a die unit having an inlet portion and an outlet portion crossing each other at 30-150 degrees so that the crystal grains have an average grain size equal to or less than 30 microns and (001) planes mostly oriented in parallel to a direction in which electric current to flow, thereby achieving the figure of merit equal to or greater than 3.0×10−3/K.

Abstract: A thermoelectric cooler utilizing superlattice and quantum-well materials may be deposited directly onto a die using thin-film deposition techniques. The materials may have a figure-of-merit of greater than one.

Abstract: A thermoelectric material is disclosed that is manufactured from a method including the steps of: providing a Group IV element boride, and doping the Group IV element boride with a doping element chosen from one of the column III, IV, V elements, wherein the doping element is different from the Group IV element in the Group IV element boride, and the doping element is not boron. An alternate method of fabricating a thermoelectric material includes the steps of simultaneously growing on a substrate a Group IV element boride and at least one doping element chosen from one of the Group III, IV, or V elements wherein the doping element is different than the Group IV element in the Group IV element boride and the doping element is not boron.

Abstract: A thermoelectric conversion unit comprising a thermoelectric conversion device 1 having a cleavage plane 2 and electrodes 3 formed on a pair of opposing surfaces of the thermoelectric conversion device 1, the angle subtended by the electrode-forming surfaces 4 of the thermoelectric conversion device 1 and by the cleavage plane 2 being not smaller than 45 degrees, the surface roughness Ra on the electrode-forming surfaces 4 being from 0.1 to 5 &mgr;m, and the electrodes 3 having a thickness larger than a maximum surface roughness Rmax of the electrode-forming surfaces 4. The thermoelectric conversion unit features a high adhesion strength between the thermoelectric conversion device 1 and the electrodes 3, and high reliability.

Abstract: A cuboid p-type and an n-type thermoelectric conversion material having a composite of an alloy powder for a rare earth magnet and a bismuth-based thermoelectric conversion material that has been rendered a p-type semiconductor or an n-type semiconductor by the addition of the required dopant, are arranged alternately with a material with low thermal conductivity and high electrical resistivity interposed between them. The low- and the high-temperature sides of these thermoelectric conversion materials are connected with wires, a magnetic field is applied in the x axis direction, a temperature gradient ∇T is imparted in the z axis direction a p-n junction is created, and thermoelectromotive force is extracted from the connection end in a plane in the y axis direction. There is a marked increase in the Seebeck coefficient even though no magnetic field is applied externally.

Abstract: A thermoelectric microactuator on a substrate includes a first temperature control element having a first surface bonded to the substrate and having a second surface. A first electrically nonconductive layer has a first surface bonded to the second surface of the first temperature control element and has a second surface. An actuator arm includes a first region bonded to the second surface of the first nonconductive layer and includes a flexure contiguously extending from the first region to an end cantilevered beyond the first nonconductive layer and forming an axis at the junction of the flexure and the first region. The first temperature control element controls the temperature of the actuator arm to thereby deflect the flexure about the axis.

Abstract: A thermoelectric module including a couple formed between two bismuth telluride thermoelectrodes. The first thermoelectrode is doped with palladium, selenium, or a combination of the two. The second thermoelectrode is doped with antimony, gold, or a combination of the two. Multiple thermoelectric modules may be used in series and parallel to achieve the desired voltage and current outputs.

Abstract: A process for producing a thermoelectric material based on two or more elements selected in the group constituted by Bi, Sb, Te and Se, which process comprises: i. an alloying step wherein determined amounts of the elements Bi, Sb, Te or Se are mixed until an homogenous powdered alloy is obtained; ii. an extrusion step of the powdered homogenous alloy obtained in the preceding step. The elements Bi, Sb, Te or Se being preferably mechanically mixed in an homogenous powdered alloy. The thermoelectric material, which are obtainable by this process, exhibits improved thermoelectric and mechanical properties and are therefore suitable, for example, as cooler, as temperature stabilizer in a electronic device or as power generator.

Abstract: Thermoelectric material is produced through a process sequence including a liquid quenching, a primary solidification such as a hot pressing or extrusion and an upset forging; although the C-planes of the crystal grains are directed in parallel to the direction in which the force is exerted on flakes during the hot pressing/extrusion, the a-axes are randomly directed; the a-axes are oriented in a predetermined direction through the upset forging; this results in improvement of electric resistivity without reduction in the figure of merit.

Abstract: A high-efficiency thermoelectric unicouple is used for power generation. The unicouple is formed with a plurality of legs, each leg formed of a plurality of segments. The legs are formed in a way that equalized certain aspects of the different segments. Different materials are also described.

Abstract: The thermoelectric properties (resistivity, thermopower and thermal conductivity) of single crystals of the low-dimensional pentatelluride materials are disclosed. The pentatellurides are well suited for use in thermoelectric devices. In general, the pentatellurides include hafnium pentatelluride and zirconium pentatelluride, which can both be substituted with selective amounts of various metals, including titanium, selenium, and antimony.

Abstract: Chevrel phase materials are used as thermoelectric materials. The Chevrel phase materials are formed as units, and the units include voids between the units. Those voids may be filled with filling elements. The filling elements can be large elements such as lead, or smaller elements such as metals. Exemplary metals may include Cu, Ti, and/or Fe. Different Chevrel phase materials are discussed, including Mo based Chevrel phase materials and Re based Chevrel phase materials.

Abstract: Quantum-dot superlattice (QLSL) structures having improved thermoelectric properties are described. In one embodiment, PbSexTe1−x/PbTe QDSLs are provided having enhanced values of Seebeck coefficient and thermoelectric figure of merit (ZT) relative to bulk values.

Abstract: Thermoelectric material of (Bi, Sb)(Te, Se) system is produced through a liquid quenching method and an extrusion from a die unit having an inlet portion and an outlet portion crossing each other at 30-150 degrees so that the crystal grains have an average grain size equal to or less than 30 microns and (001) planes mostly oriented in parallel to a direction in which electric current to flow, thereby achieving the figure of merit equal to or greater than 3.0×10−3/K.

Abstract: A thermoelectric device with improved efficiency is provided. In one embodiment, the thermoelectric device includes an electrical conductor thermally coupled to a cold plate and a thermoelement electrically coupled to the electrical conductor. The thermoelement is constructed from a thermoelectric material and has a plurality of tips through which the thermoelement is electrically coupled to the electrical conductor. The thermoelectric tips provide a low resistive connection while minimizing thermal conduction between the electrical conductor and the thermoelement.

Abstract: A process for producing a thermoelectric material comprising mixing at least two of bismuth, tellurium, selenium, and antimony and, if desired, a dopant, melting the mixture, grinding the resulting alloy ingot, forming the powder, and sintering the green body under normal pressure, or hot pressing the powder, wherein the grinding and the normal sintering or hot pressing are carried out in the presence of a solvent represented by CnH2n+1OH or CnH2n+2CO (wherein n is 1, 2 or 3).

Abstract: Ternary tellurium compounds and ternary selenium compounds may be used in fabricating thermoelectric devices with a thermoelectric figure of merit (ZT) of 1.5 or greater. Examples of such compounds include Tl2SnTe5, Tl2GeTe5, K2SnTe5 and Rb2SnTe5. These compounds have similar types of crystal lattice structures which include a first substructure with a (Sn, Ge) Te5 composition and a second substructure with chains of selected cation atoms. The second substructure includes selected cation atoms which interact with selected anion atoms to maintain a desired separation between the chains of the first substructure. The cation atoms which maintain the desired separation between the chains occupy relatively large electropositive sites in the resulting crystal lattice structure which results in a relatively low value for the lattice component of thermal conductivity (&kgr;g).

Abstract: Ternary tellurium compounds and ternary selenium compounds may be used in fabricating thermoelectric devices with a thermoelectric figure of merit (ZT) of 1.5 or greater. Examples of such compounds include Tl2SnTe5, Tl2GeTe5, K2SnTe5 and Rb2SnTe5. These compounds have similar types of crystal lattice structures which include a first substructure with a (Sn, Ge) Te5 composition and a second substructure with chains of selected cation atoms. The second substructure includes selected cation atoms which interact with selected anion atoms to maintain a desired separation between the chains of the first substructure. The cation atoms which maintain the desired separation between the chains occupy relatively large electropositive sites in the resulting crystal lattice structure which results in a relatively low value for the lattice component of thermal conductivity (&kgr;g).

Abstract: A method of fabricating a thermoelectric element with a higher thermoelectric performance than that of a conventional thermoelectric element. This fabrication method includes the steps of: (a) preparing a thermoelectric material having a predetermined composition; and (b) applying extruding pressure to the thermoelectric material in a first direction to extrude it through a die having, in an area which is not less than half of a deforming area of the thermoelectric material in the first direction, a maximum strain rate within +30% of an average strain rate so as to plastically deform the thermoelectric material into an extruded product of the thermoelectric material.

Abstract: Quantum-dot superlattice (QLSL) structures having improved thermoelectric properties are described. In one embodiment, PbSexTe1-x/PbTe QDSLs are provided having enhanced values of Seebeck coefficient and thermoelectric figure of merit (ZT) relative to bulk values. The structures can be combined into multi-chip devices to provide additional thermoelectric performance.

Abstract: A thermoelectric device with enhanced structured interfaces for improved cooling efficiency is provided. In one embodiment, the thermoelectric device includes a first thermoelement comprising a supetlattice of p-type thermoelectric material and a second thermoelement comprising superlattice of n-type thermoelectric material. The first and second thermoelements are electrically coupled to each other. The first thermoelement is proximate to, without necessarily being in physical contact with, a first array of electrically conducting tips at a discrete set of points. A planer surface of the second thermoelement is proximate to, without necessarily being in physical contact with, a second array of electrically conducting tips at a discrete set of points. The electrically conducting tips are coated with a material that has the same Seebeck coefficient as the material of the nearest layer of the superlattice to the tip.

Abstract: A thermoelectric module including a couple formed between two bismuth telluride thermoelectrodes. The first thermoelectrode is doped with palladium, selenium, or a combination of the two. The second thermoelectrode is doped with antimony, gold, or a combination of the two. Multiple thermoelectric modules may be used in series and parallel to achieve the desired voltage and current outputs.

Abstract: A class of thermoelectric compounds based on the skutterudite structure with heavy filling atoms in the empty octants and substituting transition metals and main-group atoms. High Seebeck coefficients and low thermal conductivities are achieved in combination with large electrical conductivities in these filled skutterudites for large ZT values. Substituting and filling methods are disclosed to synthesize skutterudite compositions with desired thermoelectric properties. A melting and/or sintering process in combination with powder metallurgy techniques is used to fabricate these new materials.

Abstract: An energy converting circuit, boosting the voltage supplied by a low direct voltage source, comprising a self-oscillating circuit, operating at very low voltage, using a voltage boosting transformer generating control signals of two chopper-boosters operating alternately. The circuit including an enhancement-type field effect translator used in synchronous switching with the self-oscillating circuit, which is in serial connection with an inductive resistor to the terminals of the source (1). The transistor being connected to a user circuit via a diode (15, 16). The circuit is used in a device for supplying electricity to appliances and by the production of thermal converters for the utilization of low-voltage thermoelectricity, as well as in a method for the manufacture of thermal converters on an industrial scale.

Abstract: A family of isostructural compounds have been prepared having the general formula AnPbmBinQ2n+m. These compounds possess a NaCl lattice type structure as well as low thermal conductivity and controlled electrical conductivity. Furthermore, the electrical properties can be controlled by varying the values for n and m. These isostructural compounds can be used for semiconductor applications such as detectors, lasers and photovoltaic cells. These compounds also have enhanced thermoelectric properties making them excellent semiconductor materials for fabrication of thermoelectric devices.

Abstract: Thermoelectric materials having a high performance index and thermoelectric elements are provided. The present thermoelectric materials are constituted by at least one element selected from the group consisting of Bi and Sb, at least one element selected from the group consisting of Te and Se, and, if necessary, at least one element selected from the group consisting of I, Cl, Hg, Br, Ag, and Cu. The long axis of each crystal grain of the thermoelectric material grows in the direction parallel to the pressing direction at the time of press formation, and the aspect ratio D/d of each crystal grain, which represents a ratio between the average crystal grain size along the long axis D to the average crystal grain size along the short axis d, is more than 1.5. The C-plane is oriented parallel to the pressing direction.

Abstract: A device for generating power to run an electronic component. The device includes a heat-conducting substrate (composed, e.g., of diamond or another high thermal conductivity material) disposed in thermal contact with a high temperature region. During operation, heat flows from the high temperature region into the heat-conducting substrate, from which the heat flows into the electrical power generator. A thermoelectric material (e.g., a Bi2Te3-based film or other thermoelectric material) is placed in thermal contact with the heat-conducting substrate. A low temperature region is located on the side of the thermoelectric material opposite that of the high temperature region. The thermal gradient generates electrical power and drives an electrical component.

Abstract: This invention provides a complex oxide comprising the features of: (i) being represented by the formula: Ca3-xRExCo4Oy wherein RE is a rare earth element, 0≦x≦0.5 and 8.5≦y≦10, (ii) having a Seebeck coefficient of 100 &mgr;V/K or more at a temperature of 300° C. or higher, and (iii) having an electric conductivity of 103 S/m or more at a temperature of 300° C. or higher. The complex oxide is composed of low-toxicity elements, excellent in heat resistance and chemical durability and high in thermoelectric conversion efficiency.

Abstract: A thermoelectric semiconductor material having sufficient strength and performance and high production yield. The thermoelectric semiconductor material is characterized in that a sintered powder material of a thermoelectric semiconductor having a rhombohedral structure (or hexagonal structure) is hot-forged and plastically deformed to direct either the crystals of the sintered powder structure or the subcrystals constructing the crystals in a crystal orientation having an excellent figure of merit.

Abstract: A thermoelectric semiconductor compound is provided whose performance index Z is remarkably improved without sacrificing Seebeck coefficient, electrical conductivity or thermal conductivity. The thermoelectric semiconductor compound includes a first thermoelectric semiconductor which is in the form of matrix and a second thermoelectric semiconductor which is in the form of particles dispersed in the matrix. The first thermoelectric semiconductor and the second thermoelectric semiconductor have a common element. The average diameter D of the dispersed particles complies with a formula of A<D<B, where A is the mean free path of a carrier in a single crystal of the second thermoelectric semiconductor and B is the mean free path of a long wave length phonon in the single crystal of the second thermoelectric semiconductor. A method for making the a thermoelectric semiconductor compound is provided.

Abstract: An improved material for a thermoelectric device and thermoelectric systems incorporating the same.

Abstract: Ternary tellurium compounds and ternary selenium compounds may be used in fabricating thermoelectric devices with a thermoelectric figure of merit (ZT) of 1.5 or greater. Examples of such compounds include Tl2SnTe5, Tl2GeTe5, K2SnTe5 and Rb2SnTe5. These compounds have similar types of crystal lattice structures which include a first substructure with a (Sn, Ge) Te5 composition and a second substructure with chains of selected cation atoms. The second substructure includes selected cation atoms which interact with selected anion atoms to maintain a desired separation between the chains of the first substructure. The cation atoms which maintain the desired separation between the chains occupy relatively large electropositive sites in the resulting crystal lattice structure which results in a relatively low value for the lattice component of thermal conductivity (&kgr;g).

Abstract: A process for producing a sintered thermoelectric semiconductor includes a first step of forming bulk crystals of a thermoelectric semiconductor and a second step of hot extrusion. The second step includes substeps of placing the bulk crystals in the cavity of a heated extrusion die, pushing the ram into the cavity, thereby compressing and crushing the bulk crystals and turning them into a molten or semi-molten state, and finally extruding the molten or semi-molten crystals, thereby sintering them and forming a sintered thermoelectric semiconductor.

Abstract: A class of thermoelectric compounds based on the skutterudite structure with heavy filling atoms in the empty octants and substituting transition metals and main-group atoms. High Seebeck coefficients and low thermal conductivities are achieved in combination with large electrical conductivities in these filled skutterudites for large ZT values. Substituting and filling methods are disclosed to synthesize skutterudite compositions with desired thermoelectric properties. A melting and/or sintering process in combination with powder metallurgy techniques is used to fabricate these new materials.

Abstract: Current leads are used for connecting a power supply placed in a room-temature environment and a superconducting coil placed in an ultralow-temperature environment. The current leads includes a first current lead and a second current lead. The first current lead is made up of a room-temperature N-type thermoelectric semiconductor, a low-temperature N-type thermoelectric semiconductor, and a high-temperature superconductor. The second current lead is made up of a room-temperature P-type thermoelectric semiconductor, a low-temperature P-type thermoelectric semiconductor, and a high-temperature superconductor. At least one of the first and second current leads is formed of a functionally gradient material.

Abstract: A superlattice structure having a relatively high thermoelectric figure of merit and suitable for usage in power generation systems, and in heating and/or cooling applications is described. The superlattice structure includes a first plurality of layers formed from material D.sub.z J.sub.1-z, a second plurality of layers formed from material L.sub.x M.sub.1-x D.sub.z J.sub.1-z and a third plurality of layers formed from material L.sub.x M.sub.1-x D.sub.z J.sub.1-z wherein D is a non-metal chalcogen, and wherein J is a non-metal chalcogen, and wherein L is a group IV metal selected from the group of Pb, Sn, and Ge, and wherein M is a Group IV metal selected from the group of Pb, Sn, and Ge, and wherein D is not the same as J, and wherein L is not the same as M, and wherein 0.ltoreq.x.ltoreq.1 and 0.ltoreq.z.ltoreq.1.

Abstract: Thermodynamically metastable skutterudite crystalline-structured compounds are disclosed having preselected stoichiometric compositions and superior and optimizable thermoelectric properties. The compounds are formed at low nucleation temperatures and satisfy the formula:M.sub.1-x M'.sub.4-y Co.sub.y M".sub.12wherein:M=any metal, metalloid, or mixture thereof, except for La, Ce, Pr, Nd, and Eu when x=0, and M'=Fe, Ru, or Os, and M"=Sb, P, or As;M'=Fe, Ru, Os, Rh, or mixture thereof;M"Sb, As, P, Bi, Ge.sub.0.5-w Se.sub.0.5+w, wherein w=0 to 0.5 or mixture thereof;x=0 to 1;y=0 to 4; andwherein M' and/or M" are doped or undoped. These compounds generally have the crystalline structure of a skutterudite, wherein the crystalline structure is cubic with 34 atoms in the unit-cell in the space group Im3. The M".sub.12 atoms occupy unit-cell sites 24(g), the M'.sub.4-y atoms form a cubic sublattice occupying unit-cell sites 8(c), and the M.sub.

Abstract: Molten thermoelectric alloy expressed as (Bi, Sb).sub.2 (Te, Se).sub.3 is rapidly cooled at 10.sup.4 to 10.sup.6 .degree. K/second so as to crystallize the thermoelectric alloy, and powder of the thermoelectric alloy is hot pressed under the pressure equal to or greater than 400 kgf/cm.sup.2 at 200 degrees to 400 degrees in centigrade for a time period between {(-T/5)+90} minutes and 150 minutes or at 400 degrees to 500 degrees in centigrade for a time period between 5 minutes and 150 minutes so as to increase the figure of merit by virtue of the strain left in the crystal and/or micro crystal grain.

Abstract: A superlattice structure comprising alternating layers of material such as (PbEuTeSe).sub.m and (BiSbn).sub.n where m and n are the number of PbEuTeSe and BiSb monolayers per superlattice period. For one superlattice structure the respective quantum barrier layers may be formed from electrical insulating material and the respective quantum well layers may be formed from semimetal material. For some applications superlattice structures with 10,000 or more periods may be grown. For example, the superlattice structure may comprise alternating layers of (Pb.sub.1-y Eu.sub.y Te.sub.1-z Se.sub.z).sub.m and (Bi.sub.x Sb.sub.1-x).sub.n. According to one embodiment, the superlattice structure may comprise a plurality of layers comprising m layers of (Pb.sub.1-y Eu.sub.y Te.sub.1-z Se.sub.z).sub.m and n layers of Bi.sub.0.9 Sb.sub.0.1, where m and n are preferably between 2 and 20, grown on a BaF.sub.2 substrate with a buffer layer of PbTe separating the substrate and the superlattice structure.