Abstract: RF susceptors manufactured by means of 3D printing. 3D-printed susceptors in accordance with the invention include susceptors having solid or mesh walls, where the susceptors are in the form of hollow cylinders, pyramids, spheres, hemispheres, ellipsoids, paraboloids, toroids, or prisms; flat planes; or other hollow or solid three-dimensional shapes. The 3D-printed susceptors can be formed from any suitable starting material, such as tungsten powder, graphite, silicon carbide, molybdenum powder, tantalum powder, rhenium powder, or alloys thereof, or can be formed such that some portions of the susceptors are formed from one or more materials while other portions are formed from different material(s).

Abstract: A bipolar nanocomposite semiconductor (BNS) material in which electrons and holes are separately transported throughout the BNS volume via an interpenetrating plurality of networks, where some of the networks have one conductivity type and others have the opposite conductivity type. The interpenetrating networks can include one or more multiple nanocrystalline structures, metal and dielectric networks and are intimately connected to enable band-like transport of both electrons and holes throughout the material.

Abstract: Methods of preventing hydrogen penetration into a material during high-temperature processing such as annealing of an ion-implanted GaN sample. In some embodiments, a hydrogen getter that can withstand the high temperatures is used, where the getter includes a getter material which can capture hydrogen from the annealing ambient before it can diffuse into the material, a surface layer to prevent damage to the getter from exposure to nitrogen in the annealing ambient and further includes an intermediate barrier layer to prevent mixing of the getter material and a surface layer in order to protect the getter during the high-temperature processing. In other embodiments, a hydrogen-blocking layer situated adjacent to the material being processed is used, where the hydrogen-blocking layer prevents hydrogen from the ambient from penetrating into the material.

Abstract: Methods of preventing hydrogen penetration into a material during high-temperature processing such as annealing of an ion-implanted GaN sample. In some embodiments, a hydrogen getter that can withstand the high temperatures is used, where the getter includes a getter material which can capture hydrogen from the annealing ambient before it can diffuse into the material, a surface layer to prevent damage to the getter from exposure to nitrogen in the annealing ambient and further includes an intermediate barrier layer to prevent mixing of the getter material and a surface layer in order to protect the getter during the high-temperature processing. In other embodiments, a hydrogen-blocking layer situated adjacent to the material being processed is used, where the hydrogen-blocking layer prevents hydrogen from the ambient from penetrating into the material.

Abstract: Methods for efficient doping of wide-bandgap (WBG) and ultrawide-bandgap (UWBG) semiconductors by implantation, and WBG and UWBG semiconductors made using the disclosed methods. A p-type semiconductor region is formed by implanting specified acceptor and donor co-dopant atoms in a predetermined ratio, e.g., two acceptors to one donor (ADA), into the semiconductor lattice. An n-type type semiconductor region is by implanting specified donor and acceptor co-dopant atoms in a predetermined ratio, e.g., two donors to one acceptor (DAD), into the semiconductor lattice. Compensator atoms are also implanted into the lattice to complete formula units in the crystal lattice structure and preserve the stoichiometry of the semiconductor material. The doped material is then annealed to activate the dopants and repair any damage to the lattice that might have occurred during implantation.

Abstract: A bipolar nanocomposite semiconductor (BNS) material in which electrons and holes are separately transported throughout the BNS volume via an interpenetrating plurality of networks, where some of the networks have one conductivity type and others have the opposite conductivity type. The interpenetrating networks can include one or more multiple nanocrystalline structures, metal and dielectric networks and are intimately connected to enable band-like transport of both electrons and holes throughout the material.

Abstract: A bipolar nanocomposite semiconductor (BNS) material in which electrons and holes are separately transported throughout the BNS volume via an interpenetrating plurality of networks, where some of the networks have one conductivity type and others have the opposite conductivity type. The interpenetrating networks can include one or more multiple nanocrystalline structures, metal and dielectric networks and are intimately connected to enable band-like transport of both electrons and holes throughout the material.

Abstract: Methods for efficient doping of wide-bandgap (WBG) and ultrawide-bandgap (UWBG) semiconductors by implantation, and WBG and UWBG semiconductors made using the disclosed methods. A p-type semiconductor region is formed by implanting specified acceptor and donor co-dopant atoms in a predetermined ratio, e.g., two acceptors to one donor (ADA), into the semiconductor lattice. An n-type type semiconductor region is by implanting specified donor and acceptor co-dopant atoms in a predetermined ratio, e.g., two donors to one acceptor (DAD), into the semiconductor lattice. Compensator atoms are also implanted into the lattice to complete formula units in the crystal lattice structure and preserve the stoichiometry of the semiconductor material. The doped material is then annealed to activate the dopants and repair any damage to the lattice that might have occurred during implantation.

Abstract: Thermoelectric (TE) nanocomposite material that includes at least one component consisting of nanocrystals. A TE nanocomposite material in accordance with the present invention can include, but is not limited to, multiple nanocrystalline structures, nanocrystal networks or partial networks, or multi-component materials, with some components forming connected interpenetrating networks including nanocrystalline networks. The TE nanocomposite material can be in the form of a bulk solid having semiconductor nanocrystallites that form an electrically conductive network within the material.

Abstract: A method for growing nanocrystalline diamond (NCD) on Ga2O3 to provide thermal management in Ga2O3-based devices. A protective SiNx interlayer is deposited on the Ga2O3 before growth of the NCD layer to protect the Ga2O3 from damage caused during growth of the NCD layer. The presence of the NCD provides thermal management and enables improved performance of the Ga2O3-based device.

Abstract: A method for growing nanocrystalline diamond (NCD) on Ga2O3 to provide thermal management in Ga2O3-based devices. A protective SiNx interlayer is deposited on the Ga2O3 before growth of the NCD layer to protect the Ga2O3 from damage caused during growth of the NCD layer. The presence of the NCD provides thermal management and enables improved performance of the Ga2O3-based device.

Abstract: Thermoelectric (TE) nanocomposite material that includes at least one component consisting of nanocrystals. A TE nanocomposite material in accordance with the present invention can include, but is not limited to, multiple nanocrystalline structures, nanocrystal networks or partial networks, or multi-component materials, with some components forming connected interpenetrating networks including nanocrystalline networks. The TE nanocomposite material can be in the form of a bulk solid having semiconductor nanocrystallites that form an electrically conductive network within the material.

Abstract: A bipolar nanocomposite semiconductor (BNS) material in which electrons and holes are separately transported throughout the BNS volume via an interpenetrating plurality of networks, where some of the networks have one conductivity type and others have the opposite conductivity type. The interpenetrating networks can include one or more multiple nanocrystalline structures, metal and dielectric networks and are intimately connected to enable band-like transport of both electrons and holes throughout the material.

Abstract: A bipolar nanocomposite semiconductor (BNS) material in which electrons and holes are separately transported throughout the BNS volume via an interpenetrating plurality of networks, where some of the networks have one conductivity type and others have the opposite conductivity type. The interpenetrating networks can include one or more multiple nanocrystalline structures, metal and dielectric networks and are intimately connected to enable band-like transport of both electrons and holes throughout the material.

Abstract: A method for activating implanted dopants and repairing damage to dopant-implanted GaN to form n-type or p-type GaN. A GaN substrate is implanted with n- or p-type ions and is subjected to a high-temperature anneal to activate the implanted dopants and to produce planar n- or p-type doped areas within the GaN having an activated dopant concentration of about 1018-1022 cm?3. An initial annealing at a temperature at which the GaN is stable at a predetermined process temperature for a predetermined time can be conducted before the high-temperature anneal. A thermally stable cap can be applied to the GaN substrate to suppress nitrogen evolution from the GaN surface during the high-temperature annealing step. The high-temperature annealing can be conducted under N2 pressure to increase the stability of the GaN. The annealing can be conducted using laser annealing or rapid thermal annealing (RTA).

Abstract: A method for activating implanted dopants and repairing damage to dopant-implanted GaN to form n-type or p-type GaN. A GaN substrate is implanted with n- or p-type ions and is subjected to a high-temperature anneal to activate the implanted dopants and to produce planar n- or p-type doped areas within the GaN having an activated dopant concentration of about 1018-1022 cm?3. An initial annealing at a temperature at which the GaN is stable at a predetermined process temperature for a predetermined time can be conducted before the high-temperature anneal. A thermally stable cap can be applied to the GaN substrate to suppress nitrogen evolution from the GaN surface during the high-temperature annealing step. The high-temperature annealing can be conducted under N2 pressure to increase the stability of the GaN. The annealing can be conducted using laser annealing or rapid thermal annealing (RTA).

Abstract: Thermoelectric (TE) nanocomposite material that includes at least one component consisting of nanocrystals. A TE nanocomposite material in accordance with the present invention can include, but is not limited to, multiple nanocrystalline structures, nanocrystal networks or partial networks, or multi-component materials, with some components forming connected interpenetrating networks including nanocrystalline networks. The TE nanocomposite material can be in the form of a bulk solid having semiconductor nanocrystallites that form an electrically conductive network within the material.

Abstract: Thermoelectric (TE) nanocomposite material that includes at least one component consisting of nanocrystals. A TE nanocomposite material in accordance with the present invention can include, but is not limited to, multiple nanocrystalline structures, nanocrystal networks or partial networks, or multi-component materials, with some components forming connected interpenetrating networks including nanocrystalline networks. The TE nanocomposite material can be in the form of a bulk solid having semiconductor nanocrystallites that form an electrically conductive network within the material.

Abstract: Methods for efficient doping of wide-bandgap (WBG) and ultrawide-bandgap (UWBG) semiconductors by implantation, and WBG and UWBG semiconductors made using the disclosed methods. A p-type semiconductor region is formed by implanting specified acceptor and donor co-dopant atoms in a predetermined ratio, e.g., two acceptors to one donor (ADA), into the semiconductor lattice. An n-type type semiconductor region is by implanting specified donor and acceptor co-dopant atoms in a predetermined ratio, e.g., two donors to one acceptor (DAD), into the semiconductor lattice. Compensator atoms are also implanted into the lattice to complete formula units in the crystal lattice structure and preserve the stoichiometry of the semiconductor material. The doped material is then annealed to activate the dopants and repair any damage to the lattice that might have occurred during implantation.

Abstract: Thermoelectric (TE) nanocomposite material that includes at least one component consisting of nanocrystals. A TE nanocomposite material in accordance with the present invention can include, but is not limited to, multiple nanocrystalline structures, nanocrystal networks or partial networks, or multi-component materials, with some components forming connected interpenetrating networks including nanocrystalline networks. The TE nanocomposite material can be in the form of a bulk solid having semiconductor nanocrystallites that form an electrically conductive network within the material.