Abstract: A process for manufacturing a thermoelectric material having a plurality of grains and grain boundaries. The process includes determining a material composition to be investigated for the thermoelectric material and then determining a range of values of grain size and/or grain boundary barrier height obtainable for the material composition using current state of the art manufacturing techniques. Thereafter, a range of figure of merit values for the material composition is determined as a function of the range of values of grain size and/or grain boundary barrier height. And finally, a thermoelectric material having the determined material composition and an average grain size and grain boundary barrier height corresponding to the maximum range of figure of merit values is manufactured.

Abstract: A process for manufacturing a thermoelectric material having a plurality of grains and grain boundaries. The process includes determining a material composition to be investigated for the thermoelectric material and then determining a range of values of grain size and/or grain boundary barrier height obtainable for the material composition using current state of the art manufacturing techniques. Thereafter, a range of figure of merit values for the material composition is determined as a function of the range of values of grain size and/or grain boundary barrier height. And finally, a thermoelectric material having the determined material composition and an average grain size and grain boundary barrier height corresponding to the maximum range of figure of merit values is manufactured.

Abstract: A process for manufacturing a nanocomposite thermoelectric material having a plurality of nanoparticle inclusions. The process includes determining a material composition to be investigated for the nanocomposite thermoelectric material, the material composition including a conductive bulk material and a nanoparticle material. In addition, a range of surface roughness values for the insulating nanoparticle material that can be obtained using current state of the art manufacturing techniques is determined. Thereafter, a plurality of Seebeck coefficients, electrical resistivity values, thermal conductivity values and figure of merit values as a function of the range of nanoparticle material surface roughness values is calculated. Based on these calculated values, a nanocomposite thermoelectric material composition or ranges of compositions is/are selected and manufactured.

Abstract: A process for manufacturing a nanocomposite thermoelectric material having a plurality of nanoparticle inclusions. The process includes determining a material composition to be investigated for the nanocomposite thermoelectric material, the material composition including a conductive bulk material and a nanoparticle material. In addition, a range of surface roughness values for the insulating nanoparticle material that can be obtained using current state of the art manufacturing techniques is determined. Thereafter, a plurality of Seebeck coefficients, electrical resistivity values, thermal conductivity values and figure of merit values as a function of the range of nanoparticle material surface roughness values is calculated. Based on these calculated values, a nanocomposite thermoelectric material composition or ranges of compositions is/are selected and manufactured.

Abstract: A nanocomposite thermoelectric conversion material composed of a Bi2(Te1-xSex)3 thermoelectric conversion material (where 0?x<1) as a matrix in which ceramic phonon scattering particles are dispersed. The nanocomposite thermoelectric conversion material produced by adjusting a first aqueous solution of a Bi complex to a higher pH value than an isoelectric point of phonon scattering particles, adding phonon scattering particles not modified on their surface to the pH adjusted first aqueous solution, and mixing the first aqueous solution to which phonon scattering particles have been added and a second aqueous solution including at least the former of Te anions and Se anions.

Abstract: A process for manufacturing a nanocomposite thermoelectric material having a plurality of nanoparticle inclusions. The process includes determining a material composition to be investigated for the nanocomposite thermoelectric material, the material composition including a conductive bulk material and a nanoparticle material. In addition, a range of surface roughness values for the insulating nanoparticle material that can be obtained using current state of the art manufacturing techniques is determined. Thereafter, a plurality of Seebeck coefficients, electrical resistivity values, thermal conductivity values and figure of merit values as a function of the range of nanoparticle material surface roughness values is calculated. Based on these calculated values, a nanocomposite thermoelectric material composition or ranges of compositions is/are selected and manufactured.

Abstract: A process for manufacturing a thermoelectric material having a plurality of grains and grain boundaries. The process includes determining a material composition to be investigated for the thermoelectric material and then determining a range of values of grain size and/or grain boundary barrier height obtainable for the material composition using current state of the art manufacturing techniques. Thereafter, a range of figure of merit values for the material composition is determined as a function of the range of values of grain size and/or grain boundary barrier height. And finally, a thermoelectric material having the determined material composition and an average grain size and grain boundary barrier height corresponding to the maximum range of figure of merit values is manufactured.

Abstract: A method of producing a nanocomposite thermoelectric conversion material includes preparing a solution that contains salts of a plurality of first elements constituting a thermoelectric conversion material, and a salt of a second element that has a redox potential lower than redox potentials of the first elements; precipitating the first elements, thereby producing a matrix-precursor that is a precursor of a matrix made of the thermoelectric conversion material, by adding a reducing agent to the solution; precipitating the second element in the matrix-precursor, thereby producing slurry containing the first elements and the second element, by further adding the reducing agent to the solution; and alloying the plurality of the first elements, thereby producing the matrix (70) made of the thermoelectric conversion material, and producing nano-sized phonon-scattering particles (80) including the second element, which are dispersed in the matrix (70), by filtering and washing the slurry, and then, heat-treating t

Abstract: The invention provides a nanocomposite thermoelectric conversion material (1) in which the matrix has a polycrystalline structure, and crystal grains (10) and a crystal grain boundary phase (12) of a different composition are present therein, and in which the same type of phonon-scattering particles (14) are dispersed within the crystal grains (10) and the crystal grain boundary phase (12).

Abstract: A nanocomposite thermoelectric conversion material includes a matrix and semiconductor nanowires dispersed as a dispersant in the matrix. The semiconductor nanowires are arranged unidirectionally in a long axis direction of the semiconductor nanowires.

Abstract: A nanocomposite thermoelectric conversion material (100) includes a crystalline matrix (102) made of a thermoelectric conversion material; and phonon-scattering particles (108) dispersed in the crystalline matrix (102). Each phonon-scattering particle (108) includes at least one amorphous nanoparticle (106) coated with a crystalline film (104) having a nano-order thickness, and the crystalline structure of the crystalline film (104) is different from the crystalline structure of the thermoelectric conversion material.

Abstract: A nanocomposite thermoelectric conversion material includes a matrix of the thermoelectric conversion material; and a dispersed material that is dispersed in the matrix of the thermoelectric conversion material, and that is in a form of nanoparticles. Roughness of an interface between the matrix of the thermoelectric conversion material and the nanoparticles of the dispersed material is equal to or larger than 0.1 nm.

Abstract: A thermoelectric converter is made of a first thermoelectric conversion material in which at least one type of second thermoelectric conversion material particles having an average size of 1 to 100 nm is dispersed. At least a part of the second thermoelectric conversion material particles is dispersed at a distance not more than the mean free path of the phonons of the first thermoelectric conversion material.

Abstract: A nanocomposite thermoelectric conversion material capable of improving enhancement of ZT by reducing the thermal conductivity is provided by a production method for a nanocomposite thermoelectric conversion material composed of a matrix and a nanoparticle, the method comprising selecting the combination of at least three kinds of elements such that out of, one kind of an element becomes an oxide in the form of a nanoparticle; dissolving the elements such that the amount of the element constituting the nanoparticle becomes excessive with respect to the composition of the matrix in the final target product; adding a reducing agent to the solution, thereby allowing a reduction reaction to proceed at a plurality of different pH values from the initiation to the termination of reaction; and performing a hydrothermal treatment to cause formation of the matrix by alloying and formation of a nanoparticle composed of the oxide.

Abstract: A method of producing a nanocomposite thermoelectric conversion material which has a high thermoelectric conversion performance without modifying the surface of the phonon scattering particles and thereby preventing the conventional defects due to an organic phase derived from a modifier. The method produces a nanocomposite thermoelectric conversion material comprised of a Bi2(Te1-x,Sex)3 thermoelectric conversion material (where 0?x<1) as a matrix in which ceramic phonon scattering particles are dispersed, characterized by including a step of adjusting a first aqueous solution of a Bi complex to a higher pH value than an isoelectric point of phonon scattering particles, a step of adding phonon scattering particles not modified on their surface to the pH adjusted first aqueous solution, and a step of mixing the first aqueous solution to which phonon scattering particles have been added and a second aqueous solution including at least the former of Te anions and Se anions.

Abstract: A nanocomposite thermoelectric conversion material is provided in which crystal grains of a thermoelectric material parent phase are stacked in a laminar configuration and are oriented, the width of the crystal grains perpendicular to the direction of this orientation is in a range from at least 5 nm to less than 20 nm, and insulating nanoparticles are present dispersed at the grain boundaries. Also provided is a method of producing a nanocomposite thermoelectric conversion material, by which the crystal grains of a thermoelectric material parent phase are oriented by cooling a material under compression at a cooling rate of at least 1° C./minute to less than 20° C./minute. A thermoelectric conversion element that contains the aforementioned nanocomposite thermoelectric conversion material is also provided.

Abstract: A thermoelectric converter made of a thermoelectric conversion material is provided in which metal or alloy particles having an average particle size of 1 to 100 nm are dispersed, wherein at least a part of the metal or alloy particles are dispersed at a distance not more than the mean free path of the phonon of the thermoelectric conversion material.

Abstract: A process for manufacturing a nanocomposite thermoelectric material having a plurality of nanoparticle inclusions. The process includes determining a material composition to be investigated for the nanocomposite thermoelectric material, the material composition including a conductive bulk material and a nanoparticle material. In addition, a range of surface roughness values for the insulating nanoparticle material that can be obtained using current state of the art manufacturing techniques is determined. Thereafter, a plurality of Seebeck coefficients, electrical resistivity values, thermal conductivity values and figure of merit values as a function of the range of nanoparticle material surface roughness values is calculated. Based on these calculated values, a nanocomposite thermoelectric material composition or ranges of compositions is/are selected and manufactured.

Abstract: A process for manufacturing a thermoelectric material having a plurality of grains and grain boundaries. The process includes determining a material composition to be investigated for the thermoelectric material and then determining a range of values of grain size and/or grain boundary barrier height obtainable for the material composition using current state of the art manufacturing techniques. Thereafter, a range of figure of merit values for the material composition is determined as a function of the range of values of grain size and/or grain boundary barrier height. And finally, a thermoelectric material having the determined material composition and an average grain size and grain boundary barrier height corresponding to the maximum range of figure of merit values is manufactured.

Abstract: The invention provides a nanocomposite thermoelectric conversion material (1) in which the matrix has a polycrystalline structure, and crystal grains (10) and a crystal grain boundary phase (12) of a different composition are present therein, and in which the same type of phonon-scattering particles (14) are dispersed within the crystal grains (10) and the crystal grain boundary phase (12).