Abstract: Systems and methods for mitigating heat rejection limitations of a thermoelectric module are disclosed. In some embodiments, a method of operating a thermoelectric module includes providing a first amount of power to the thermoelectric module and determining that a temperature of a hot side of the thermoelectric module is above a first threshold. The method also includes, in response to determining that the temperature of the hot side is above the first threshold, providing a second amount of power to the thermoelectric module that is less than the first amount of power. The method also includes determining that the temperature of the hot side of the thermoelectric module is below a second threshold and providing a third amount of power to the thermoelectric module. In some embodiments, this mitigates heat rejection limitations of the thermoelectric module, especially when the hot side of the thermoelectric module is passively cooled.

Abstract: A method of controlling a heat exchanger including thermoelectric coolers to maintain set point temperature of a chamber. The method includes receiving temperature data indicative of a temperature of the chamber and selectively controlling two or more subsets of thermoelectric coolers based on the temperature of the chamber. Selectively controlling the two or more subsets includes operating each thermoelectric cooler in a first subset at or near the point where the coefficient of performance is maximized (QCOPmax) by providing a current or voltage with amplitude corresponding to QCOPmax (ICOPmax, VCOPmax) when the temperature of the chamber is within a predefined steady state range including the set point temperature.

Abstract: Gallium nitride material devices and methods associated with the same. In some embodiments, the devices may be transistors which include a conductive structure connected to a source electrode. The conductive structure may form a source field plate which can be formed over a dielectric material and can extend in the direction of the gate electrode of the transistor. The source field plate may reduce the electrical field (e.g., peak electrical field and/or integrated electrical field) in the region of the device between the gate electrode and the drain electrode which can lead to a number of advantages including reduced gate-drain feedback capacitance, reduced surface electron concentration, increased breakdown voltage, and improved device reliability. These advantages enable the gallium nitride material transistors to operate at high drain efficiencies and/or high output powers. The devices can be used in RF power applications, amongst others.

Abstract: Embodiments of a hybrid fan and active heat pumping system are disclosed. In some embodiments, the hybrid fan and active heat pumping system comprises a fan assembly and an active heat pumping system comprises a heat pump. The active heat pumping system is integrated with the fan assembly and is operable to actively cool or heat air as the air passes through the fan assembly. In some embodiments, the heat pump comprised in the active heat pumping system is a solid-state heat pump, a vapor compression heat pump, or a Stirling Cycle heat pump.

Abstract: Gallium nitride material devices and methods associated with the same. In some embodiments, the devices may be transistors which include a conductive structure connected to a source electrode. The conductive structure may form a source field plate which can be formed over a dielectric material and can extend in the direction of the gate electrode of the transistor. The source field plate may reduce the electrical field (e.g., peak electrical field and/or integrated electrical field) in the region of the device between the gate electrode and the drain electrode which can lead to a number of advantages including reduced gate-drain feedback capacitance, reduced surface electron to concentration, increased breakdown voltage, and improved device reliability. These advantages enable the gallium nitride material transistors to operate at high drain efficiencies and/or high output powers. The devices can be used in RF power applications, amongst others.

Abstract: Gallium nitride material devices and methods associated with the same. In some embodiments, the devices may be transistors which include a conductive structure connected to a source electrode. The conductive structure may form a source field plate which can be formed over a dielectric material and can extend in the direction of the gate electrode of the transistor. The source field plate may reduce the electrical field (e.g., peak electrical field and/or integrated electrical field) in the region of the device between the gate electrode and the drain electrode which can lead to a number of advantages including reduced gate-drain feedback capacitance, reduced surface electron concentration, increased breakdown voltage, and improved device reliability. These advantages enable the gallium nitride material transistors to operate at high drain efficiencies and/or high output powers. The devices can be used in RF power applications, amongst others.

Abstract: Systems and methods are disclosed herein relating to an Alternating Current-Direct Current (AC-DC) power conversion system for supplying power to one or more Thermoelectric Coolers (TECs). In some embodiments, a system comprises one or more TECs and an AC-DC power conversion system configured to supply power to the one or more TECs for a high efficiency mode of operation and a high heat pumping mode of operation. The AC-DC power conversion system comprises a first AC-DC power converter configured to convert an AC input to a DC output at a first output power level for the high efficiency mode of operation of the one or more TECs. The AC-DC power conversion system further comprises a second AC-DC power converter configured to convert the AC input to a DC output at a second output power level for the high heat pumping mode of operation of the one or more TECs.

Abstract: Embodiments of a hybrid fan and active heat pumping system are disclosed. In some embodiments, the hybrid fan and active heat pumping system comprises a fan assembly and an active heat pumping system comprises a heat pump. The active heat pumping system is integrated with the fan assembly and is operable to actively cool or heat air as the air passes through the fan assembly. In some embodiments, the heat pump comprised in the active heat pumping system is a solid-state heat pump, a vapor compression heat pump, or a Stirling Cycle heat pump.

Abstract: A thermoelectric refrigeration system including at least one cooling chamber and a thermoelectric heat exchange system. The thermoelectric heat exchange system includes cascaded heat sinks. The cascaded heat sinks include cascaded cold side heat sinks and a hot side heat sink. The cascaded cold side heat sinks include a first cold side heat sink and a second cold side heat sink. The thermoelectric heat exchange system also includes a first plurality of thermoelectric coolers disposed between the first cold side heat sink and the second cold side heat sink and a second plurality of thermoelectric coolers disposed between the second cold side heat sink and the hot side heat sink. Each thermoelectric cooler is a module including multiple thermoelectric devices.

Abstract: Semiconductor structures comprising a III-nitride (e.g., gallium nitride) material region and methods associated with such structures are provided. In some embodiments, the structures include an electrically conductive material (e.g., gold) separated from certain other region(s) of the structure (e.g., a silicon substrate) by a barrier material in order to limit, or prevent, undesirable reactions between the electrically conductive material and the other component(s) which can impair device performance. In certain embodiments, the electrically conductive material may be formed in a via. For example, the via can extend from a topside of the device to a backside so that the electrically conductive material connects a topside contact to a backside contact. The structures described herein may form the basis of a number of semiconductor devices including transistors (e.g., FET), Schottky diodes, light-emitting diodes and laser diodes, amongst others.

Abstract: A thermoelectric refrigeration system includes a heat exchanger that includes a cold side heat sink and a hot side heat sink. The thermoelectric refrigeration system also includes a heat exchange loop coupled to one of the cold side heat sink and the hot side heat sink, the heat exchange loop operating according to thermosiphon principles to provide passive two-phase transport of a working fluid through the heat exchange loop. The thermoelectric refrigeration system also includes thermal insulation that thermally insulates the heat exchanger from a cooling chamber of the thermoelectric refrigeration system or an environment that is external to the thermoelectric refrigeration system.

Abstract: Systems and methods for mitigating heat rejection limitations of a thermoelectric module are disclosed. In some embodiments, a method of operating a thermoelectric module includes providing a first amount of power to the thermoelectric module and determining that a temperature of a hot side of the thermoelectric module is above a first threshold. The method also includes, in response to determining that the temperature of the hot side is above the first threshold, providing a second amount of power to the thermoelectric module that is less than the first amount of power. The method also includes determining that the temperature of the hot side of the thermoelectric module is below a second threshold and providing a third amount of power to the thermoelectric module. In some embodiments, this mitigates heat rejection limitations of the thermoelectric module, especially when the hot side of the thermoelectric module is passively cooled.

Abstract: A two-phase heat exchanger includes a hot side heat sink, a cold side heat sink, and one or more thermoelectric modules disposed between the hot side heat sink and the cold sink heat sink such that hot sides of the one or more thermoelectric modules are thermally coupled to the hot side heat sink and cold sides of the one or more thermoelectric modules are thermally coupled to the cold side heat sink. The two-phase heat exchanger is configured to be mounted at an angle from vertical.

Abstract: Systems and methods are disclosed herein relating to an Alternating Current-Direct Current (AC-DC) power conversion system for supplying power to one or more Thermoelectric Coolers (TECs). In some embodiments, a system comprises one or more TECs and an AC-DC power conversion system configured to supply power to the one or more TECs for a high efficiency mode of operation and a high heat pumping mode of operation. The AC-DC power conversion system comprises a first AC-DC power converter configured to convert an AC input to a DC output at a first output power level for the high efficiency mode of operation of the one or more TECs. The AC-DC power conversion system further comprises a second AC-DC power converter configured to convert the AC input to a DC output at a second output power level for the high heat pumping mode of operation of the one or more TECs.

Abstract: Embodiments of a hybrid fan and active heat pumping system are disclosed. In some embodiments, the hybrid fan and active heat pumping system comprises a fan assembly and an active heat pumping system comprises a heat pump. The active heat pumping system is integrated with the fan assembly and is operable to actively cool or heat air as the air passes through the fan assembly. In some embodiments, the heat pump comprised in the active heat pumping system is a solid-state heat pump, a vapor compression heat pump, or a Stirling Cycle heat pump.

Abstract: A thermoelectric system includes a cooling chamber and a thermoelectric heat exchange system. The thermoelectric heat exchange system includes a hot side heat sink, a cold side heat sink that is physically separated from the hot side heat sink, and a heat conduit that thermally couples the hot side heat sink and the cold side heat sink.

Abstract: Semiconductor structures comprising a III-nitride (e.g., gallium nitride) material region and methods associated with such structures are provided. In some embodiments, the structures include an electrically conductive material (e.g., gold) separated from certain other region(s) of the structure (e.g., a silicon substrate) by a barrier material in order to limit, or prevent, undesirable reactions between the electrically conductive material and the other component(s) which can impair device performance. In certain embodiments, the electrically conductive material may be formed in a via. For example, the via can extend from a topside of the device to a backside so that the electrically conductive material connects a topside contact to a backside contact. The structures described herein may form the basis of a number of semiconductor devices including transistors (e.g., FET), Schottky diodes, light-emitting diodes and laser diodes, amongst others.

Abstract: Embodiments of the present disclosure relate to controlling multiple Thermoelectric Coolers (TECs) to maintain a set point temperature of a chamber. In one embodiment, a controller receives temperature data corresponding to a temperature of the chamber. Based on the temperature data, the controller selectively controls two or more subsets of the TECs to maintain the temperature of the chamber at a desired set point temperature. In this manner, the controller is enabled to control the TECs such that the TECs operate to efficiently maintain the temperature of the chamber at the set point temperature. In another embodiment, the controller selects one or more control schemes enabled by the controller based on temperature data and a desired performance profile. The controller then independently controls one or more subsets of the TECs according to the selected control scheme(s).

Abstract: Semiconductor structures comprising a III-nitride (e.g., gallium nitride) material region and methods associated with such structures are provided. In some embodiments, the structures include an electrically conductive material (e.g., gold) separated from certain other region(s) of the structure (e.g., a silicon substrate) by a barrier material in order to limit, or prevent, undesirable reactions between the electrically conductive material and the other component(s) which can impair device performance. In certain embodiments, the electrically conductive material may be formed in a via. For example, the via can extend from a topside of the device to a backside so that the electrically conductive material connects a topside contact to a backside contact. The structures described herein may form the basis of a number of semiconductor devices including transistors (e.g., FET), Schottky diodes, light-emitting diodes and laser diodes, amongst others.

Abstract: Embodiments of a thin-film heterostructure thermoelectric material and methods of fabrication thereof are disclosed. In general, the thermoelectric material is formed in a Group IIa and IV-VI materials system. The thermoelectric material includes an epitaxial heterostructure and exhibits high heat pumping and figure-of-merit performance in terms of Seebeck coefficient, electrical conductivity, and thermal conductivity over broad temperature ranges through appropriate engineering and judicious optimization of the epitaxial heterostructure.