Abstract: A Stirling engine includes: the thermosiphon that accommodates the heating medium receiving heat from a heat source; and an engine unit that has a body accommodating working gas. A heater that gives heat to the working gas by the heating medium is arranged in the body. The Stirling engine includes an engine controller that executes control for increasing an absorbed amount of thermal energy from the heating medium when at least one of the pressure and the temperature of the heating medium exceeds a predetermined value.

Abstract: It is an object of the present invention to provide a photoelectric conversion device and a photoelectric conversion module with enhanced conversion efficiency. The photoelectric conversion device comprises: a light-absorbing layer containing a compound semiconductor capable of photoelectric conversion; and a semiconductor layer provided on one side of the light-absorbing layer and containing sulfur, wherein more sulfur is present in part of the semiconductor layer on the aforementioned light-absorbing layer side than in part thereof on the opposite side from the aforementioned light-absorbing layer.

Abstract: [Problem] In the case of further stacking a window layer or the like on a buffer layer, the buffer layer and the light absorption layer are likely to be damaged during the formation of the window layer due to inferior moisture resistance and plasma resistance, and photoelectric conversion elements sometimes fail to achieve any satisfactory conversion efficiency in terms of reliability. [Solving Means] Provided is a photoelectric conversion element including: a light absorption layer containing a I-B group element, a III-B group element, and a VI-B group element, which is provided on a lower electrode layer; a first semiconductor layer containing a III-B group element and a VI-B group element, which is provided on the light absorption layer; and a second semiconductor layer containing an oxide of a II-B group element, which is provided on the first semiconductor layer, wherein the light absorption layer comprises a doped layer region containing the II-B group element, on the first semiconductor layer side.

Abstract: A thermoelectric element formed of a sintered body of a semiconductor comprising at least two kinds of elements selected from the group consisting of Bi, Te, Se and Sb, and having a micro-Vickers' hardness of not smaller than 0.5 GPa. The thermoelectric element has a hardness of not smaller than 0.5 GPa, and exhibits a large resistance against deformation, and is not easily broken by deformation. As a result, breakage due to deformation is prevented and a highly reliable thermoelectric element is realized even when a shape factor which is a ratio of the sectional area of the thermoelectric element to the height thereof, is increased and even when the element density is increased.

Abstract: In a wavelength converter converting a wavelength of light emitted from a light source and outputting an output light containing light whose wavelength is converted, which comprises a fluorescent substance dispersed in a transparent matrix, the fluorescent substance has semiconductor fine particles containing at least one univalent metal element selected from alkali metal and Ag, an element of group III in the periodic table selected from indium and gallium, and sulfur, and does not substantially contain Cd and Se. Hence, a wavelength converter having a conversion efficiency of equal to or more than that of a converter containing CdSe can be provided by using a semiconductor material formed of a highly safe composition.

Abstract: In a wavelength converter converting a wavelength of light emitted from a light source and outputting an output light containing light whose wavelength is converted, which comprises a fluorescent substance dispersed in a transparent matrix, the fluorescent substance has semiconductor fine particles containing at least one univalent metal element selected from alkali metal and Ag, an element of group III in the periodic table selected from indium and gallium, and sulfur, and does not substantially contain Cd and Se. Hence, a wavelength converter having a conversion efficiency of equal to or more than that of a converter containing CdSe can be provided by using a semiconductor material formed of a highly safe composition.

Abstract: A thermoelectric element formed of a sintered body of a semiconductor comprising at least two kinds of elements selected from the group consisting of Bi, Te, Se and Sb, and having a micro-Vickers' hardness of not smaller than 0.5 GPa. The thermoelectric element has a hardness of not smaller than 0.5 GPa, and exhibits a large resistance against deformation, and is not easily broken by deformation. As a result, breakage due to deformation is prevented and a highly reliable thermoelectric element is realized even when a shape factor which is a ratio of the sectional area of the thermoelectric element to the height thereof, is increased and even when the element density is increased.

Abstract: A thermoelectric element formed of a sintered body of a semiconductor comprising at least two kinds of elements selected from the group consisting of Bi, Te, Se and Sb, and having a micro-Vickers' hardness of not smaller than 0.5 GPa. The thermoelectric element has a hardness of not smaller than 0.5 GPa, and exhibits a large resistance against deformation, and is not easily broken by deformation. As a result, breakage due to deformation is prevented and a highly reliable thermoelectric element is realized even when a shape factor which is a ratio of the sectional area of the thermoelectric element to the height thereof, is increased and even when the element density is increased.

Abstract: A novel diarylethene photochromic compound is provided. The photochromic compound is capable of forming an amorphous thin film by itself through a coating method and has an excellent thermostability. The amorphous thin film of the photochromic compound can exhibit a large refractive index between the isomers of the photochromic compound. Thus, using such an amorphous thin film provides an optical function device suitable for an optical memory device and an optical switching device.