Abstract: A thermopile sensor according to the present disclosure includes a p-type portion and an n-type portion. The p-type portion has a first phononic crystal in which first holes are arranged in a plan view. The n-type portion has a second phononic crystal in which second holes are arranged in a plan view. The p-type portion and the n-type portion constitute a thermocouple. The boundary scattering frequency of phonons in the first phononic crystal is different from the boundary scattering frequency of phonons in the second phononic crystal. Alternatively, the ratio of the sum of the areas of the first holes to the area of the first phononic crystal in a plan view is different from the ratio of the sum of the areas of the second holes to the area of the second phononic crystal in a plan view.

Abstract: A thermoelectric conversion element includes a p-type thermoelectric converter, an n-type thermoelectric converter, a first electrode, a second electrode, and a third electrode. One end of the p-type converter is electrically connected to one end of the n-type converter. The other end of the p-type converter is electrically connected to the second electrode, and the other end of the n-type converter is electrically connected to the third electrode. The p-type converter includes a first phononic crystal layer having a first phononic crystal structure including regularly arranged first through holes. The n-type converter includes a second phononic crystal layer having a second phononic crystal structure including regularly arranged second through holes. The through direction of the first through holes is a direction extending between the ends of the p-type converter. The through direction of the second through holes is a direction extending between the ends of the n-type converter.

Abstract: An infrared sensor according to the present disclosure includes a transistor, a cavity layer, and a sensor layer. The cavity layer includes a cavity. The sensor layer includes a phononic crystal in which holes are arranged. In plan view, the infrared sensor includes a first region and a second region. The first region includes a transistor. The second region includes the cavity. The cavity layer includes a flat major surface. The major surface is disposed around the cavity, and extends across both the first region and the second region. The sensor layer is disposed on the major surface.

Abstract: An infrared sensor includes: a base substrate; a bolometer infrared receiver; a first beam; and a second beam. Each of the first and second beams has a connection portion connected to the base substrate and/or a member on the base substrate and a separated portion away from the base substrate, and is physically joined to the infrared receiver at the separated portion. The infrared receiver is supported by the first and second beams to be away from the base substrate. The infrared receiver includes a resistance change portion including a resistance change material the electrical resistance of which changes with temperature. The resistance change portion includes an amorphous semiconductor, and the first and second beams include a crystalline semiconductor made of the same base material as the resistance change material, and is electrically connected to the resistance change portion at the separated portion.

Abstract: A multilayer body of the present disclosure includes a phononic crystal layer and a metal layer. The phononic crystal layer has a plurality of recesses. The metal layer is disposed on or above the phononic crystal layer. Metal atoms of a kind identical to that of metal atoms contained in the metal layer are present inside the recesses.

Abstract: A solid material includes a three-dimensional structure including recesses and a solid portion formed between the recesses, the three-dimensional structure adjusting a thermal conductivity of the solid material by interaction with phonons, wherein a minimum size of the solid portion between the recesses adjacent to each other in plan view of the three-dimensional structure is smaller than or equal to 100 nm, and the solid portion includes a region with a Young's modulus being smaller than or equal to 80% of a Young's modulus of a reference sample that is fabricated by using the same type of material as a material of the solid portion without forming any recesses.

Abstract: An infrared sensor includes a base substrate, an infrared light receiver, and a beam. The beam includes a separated portion separated from the base substrate to be suspended above the base substrate. The beam is connected at the separated portion to the infrared light receiver. The beam includes a p-type portion containing a p-type semiconductor and an n-type portion containing an n-type semiconductor. The p-type portion has a first three-dimensional structure including first recesses and a first solid portion formed between the first recesses. The first solid portion has, between the first recesses adjacent to each other in plan view, a smallest dimension of less than or equal to 100 nanometers in plan view. The n-type portion has a second three-dimensional structure including second recesses and a second solid portion formed between the second recesses.

Abstract: An infrared sensor is provided with an infrared light receiver, a signal pathway, and a first member. The infrared light receiver has a structure in which at least two materials having different coefficients of thermal expansion are layered. The signal pathway includes a first signal pathway allowing passage of a driving signal to be applied to the infrared light receiver. The driving signal has a current value equal to or greater than a prescribed magnitude, and the infrared light receiver deforms in response to the application of the driving signal to the infrared light receiver, thereby at least a portion of the infrared light receiver contacting the first member.

Abstract: A thermoelectric conversion device includes: an insulating layer; and a thermoelectric conversion module disposed on the insulating layer. The thermoelectric conversion module has a first thermoelectric conversion region and a second thermoelectric conversion region. The first(second) thermoelectric conversion region includes one or two or more thermoelectric conversion elements, a first(third) connection electrode, and a second(fourth) connection electrode. The thermoelectric conversion elements of the first(second) thermoelectric conversion region are electrically connected to the first(third) connection electrode and the second(fourth) connection electrode and located on an electric path connecting these connection electrodes. Each of the thermoelectric conversion elements includes a thermoelectric converter.

Abstract: A thermoelectric conversion device includes: a first thermoelectric conversion module, a first insulating layer, and a second thermoelectric conversion module. The first (second) thermoelectric conversion module includes one or two or more thermoelectric conversion elements, a first (third) connection electrode, and a second (fourth) connection electrode. The thermoelectric conversion elements of the first (second) thermoelectric conversion module are electrically connected to the first (third) connection electrode and the second (fourth) connection electrode and located on an electric path connecting these connection electrodes. Each of the thermoelectric conversion elements includes a thermoelectric converter. The thermoelectric converter of at least one of the thermoelectric conversion elements has a phononic crystal layer having a phononic crystal structure including a plurality of regularly arranged through holes.

Abstract: A gas sensor includes a substrate, a support layer, a base layer, a heater layer disposed on or above the base layer, a gas sensing layer that is disposed on or above one of the heater layer and the base layer and that has a gas concentration dependent electrical impedance, and a detection electrode that is electrically connected to the gas sensing layer and that detects the impedance of the gas sensing layer. The substrate has a cavity and an opening formed by the cavity. The support layer is disposed on the substrate so as to cover at least an entire periphery of the opening. The base layer is supported by the support layer above the cavity so as to be separated from the substrate. A portion of the support layer in contact with the cavity has a first phononic crystal structure structured by a plurality of regularly arranged through-holes.

Abstract: A thermoelectric conversion element includes a p-type thermoelectric converter, an n-type thermoelectric converter, a first electrode, a second electrode, and a third electrode. One end of the p-type converter is electrically connected to one end of the n-type converter. The other end of the p-type converter is electrically connected to the second electrode, and the other end of the n-type converter is electrically connected to the third electrode. The p-type converter includes a first phononic crystal layer having a first phononic crystal structure including regularly arranged first through holes. The n-type converter includes a second phononic crystal layer having a second phononic crystal structure including regularly arranged second through holes. The through direction of the first through holes is a direction extending between the ends of the p-type converter. The through direction of the second through holes is a direction extending between the ends of the n-type converter.

Abstract: The present disclosure provides a novel multilayer body. The multilayer body of the present disclosure includes a first phononic crystal layer and a second phononic crystal layer disposed on or above the first phononic crystal layer. The first phononic crystal layer has a first phononic crystal structure including a plurality of regularly arranged first through holes. The second phononic crystal layer has a second phononic crystal structure including a plurality of regularly arranged second through holes. The through direction of the plurality of first through holes in the first phononic crystal layer is substantially parallel to the through direction of the plurality of second through holes in the second phononic crystal layer.

Abstract: Each of first and second beams has a connection portion connected to a base substrate and a separated portion away from the base substrate, and is physically joined to an infrared receiver at the separated portion. The infrared receiver is supported by the first and second beams, and includes lower electrode, upper electrode, and a resistance change film. The resistance change film is sandwiched by the lower electrode and upper electrode in a thickness direction, each of the lower and upper electrodes is electrically connected to the resistance change film, the lower and upper electrodes are electrically connected to first wiring and second wiring, respectively, at least one electrode selected from the lower electrode and the upper electrode has a line-and-space structure, and an infrared reflection film is provided at a position on a surface of the base substrate facing the infrared receiver.

Abstract: An infrared sensor includes: a base substrate; a bolometer infrared receiver; a first beam; and a second beam. Each of the first and second beams has a connection portion connected to the base substrate and/or a member on the base substrate and a separated portion away from the base substrate, and is physically joined to the infrared receiver at the separated portion. The infrared receiver is supported by the first and second beams to be away from the base substrate. The infrared receiver includes a resistance change portion including a resistance change material the electrical resistance of which changes with temperature. The resistance change portion includes an amorphous semiconductor, and the first and second beams include a crystalline semiconductor made of the same base material as the resistance change material, and is electrically connected to the resistance change portion at the separated portion.

Abstract: An infrared sensor according to the present disclosure includes base substrate, infrared receiver, and beam. The beam includes connective portion connecting with the base substrate and/or a member on the base substrate, and separated portion separated from the base substrate. The infrared receiver and the beam are joined with each other at the separated portion. The infrared receiver is supported by the beam in a state where the infrared receiver is separated from the base substrate. The beam includes junction part joined to the infrared receiver, and section positioned between junction part and the connective portion, and section includes a phononic crystal structure defined by a plurality of through holes orderly arranged. The crystal structure includes a first domain and a second domain that are phononic crystal domains.

Abstract: A device includes a semiconductor substrate containing gallium nitride and having a crystal face inclined from 0.05° to 15° inclusive with respect to the c-plane. The semiconductor substrate includes an irregular portion on the crystal face, and the contact angle of pure water having a specific resistance of 18 M?·cm or more on the surface of the irregular portion is 10° or less.

Abstract: An infrared sensor according to the present disclosure includes base substrate, infrared receiver, and beam. The beam includes connective portion connecting with the base substrate and/or a member on the base substrate, and separated portion separated from the base substrate. The infrared receiver and the beam are joined with each other at the separated portion. The infrared receiver is supported by the beam in a state where the infrared receiver is separated from the base substrate. The beam includes junction part joined to the infrared receiver, and section positioned between junction part and the connective portion, and section includes a phononic crystal structure defined by a plurality of through holes orderly arranged. The crystal structure includes a first domain and a second domain that are phononic crystal domains.

Abstract: A device includes a semiconductor substrate containing gallium nitride and having a crystal face inclined from 0.05° to 15° inclusive with respect to the c-plane. The semiconductor substrate includes an irregular portion on the crystal face, and the contact angle of pure water having a specific resistance of 18 M?·cm or more on the surface of the irregular portion is 10° or less.

Abstract: A device includes a semiconductor substrate containing gallium nitride and having a crystal face inclined from 0.05° to 15° inclusive with respect to the c-plane. The semiconductor substrate includes an irregular portion on the crystal face, and the contact angle of pure water having a specific resistance of 18 M?·cm or more on the surface of the irregular portion is 10° or less.