Abstract: A method for fabricating a semiconductor device, such as a GaN high electron mobility transistor (HEMT) device, including etching a thermal via into a back-side of a semiconductor substrate and depositing a diamond nucleation seed layer across the back-side of the substrate. The method further includes coating the diamond nucleation with a mask layer and removing mask material outside of the thermal via on the planar portions of the back-side of the substrate. The method includes removing portions of the diamond nucleation layer on the planar portions and then removing the remaining portion of the mask material in the thermal via. The method then includes depositing a bulk diamond layer within the thermal via on the remaining portion of the diamond nucleation layer so that diamond only grows in the thermal via and not on the planar portions of the substrate.

Abstract: Optical devices that include one or more structures fabricated from polar-dielectric materials that exhibit surface phonon polaritons (SPhPs), where the SPhPs alter the optical properties of the structure. The optical properties lent to these structures by the SPhPs are altered by introducing charge carriers directly into the structures. The carriers can be introduced into these structures, and the carrier concentration thereby controlled, through optical pumping or the application of an appropriate electrical bias.

Abstract: A method for fabricating a semiconductor device, such as a GaN high electron mobility transistor (HEMT) device, including etching a thermal via into a back-side of a semiconductor substrate and depositing a diamond nucleation seed layer across the back-side of the substrate. The method further includes coating the diamond nucleation with a mask layer and removing mask material outside of the thermal via on the planar portions of the back-side of the substrate. The method includes removing portions of the diamond nucleation layer on the planar portions and then removing the remaining portion of the mask material in the thermal via. The method then includes depositing a bulk diamond layer within the thermal via on the remaining portion of the diamond nucleation layer so that diamond only grows in the thermal via and not on the planar portions of the substrate.

Abstract: Optical devices that include one or more structures fabricated from polar-dielectric materials that exhibit surface phonon polaritons (SPhPs), where the SPhPs alter the optical properties of the structure. The optical properties lent to these structures by the SPhPs are altered by introducing charge carriers directly into the structures. The carriers can be introduced into these structures, and the carrier concentration thereby controlled, through optical pumping or the application of an appropriate electrical bias.

Abstract: Optical devices that include one or more structures fabricated from polar-dielectric materials that exhibit surface phonon polaritons (SPhPs), where the SPhPs alter the optical properties of the structure. The optical properties lent to these structures by the SPhPs are altered by introducing charge carriers directly into the structures. The carriers can be introduced into these structures, and the carrier concentration thereby controlled, through optical pumping or the application of an appropriate electrical bias.

Abstract: A method for reducing graphene film thickness on a donor substrate and transferring graphene films from a donor substrate to a handle substrate includes applying a bonding material to the graphene on the donor substrate, releasing the bonding material from the donor substrate thereby leaving graphene on the bonding material, applying the bonding material with graphene onto the handle substrate, and releasing the bonding material from the handle substrate thereby leaving the graphene on the handle substrate. The donor substrate may comprise SiC, metal foil or other graphene growth substrate, and the handle substrate may comprise a semiconductor or insulator crystal, semiconductor device, epitaxial layer, flexible substrate, metal film, or organic device.

Abstract: A metamaterial thin film with plasmonic properties formed by depositing metallic films by atomic layer deposition onto a substrate to form a naturally occurring mosaic-like nanostructure having two-dimensional features with air gaps between the two-dimensional features. Due to the unique deposition nanostructure, plasmonic thin films of metal or highly conducting materials can be produced on any substrate, including fabrics and biological materials. In addition, these plasmonic materials can be used in conjunction with geometric patterns that may be used to create multiple resonance plasmonic metamaterials.

Abstract: A heterojunction between thin films of NCD and 4H—SiC was developed. Undoped and B-doped NCDs were deposited on both n? and p? SiC epilayers. I-V measurements on p+ NCD/n? SiC indicated Schottky rectifying behavior with a turn-on voltage of around 0.2 V. The current increased over eight orders of magnitude with an ideality factor of 1.17 at 30° C. Ideal energy-band diagrams suggested a possible conduction mechanism for electron transport from the SiC conduction band to either the valence band or acceptor level of the NCD film.

Abstract: A plasmonic grating sensor having periodic arrays of vertically aligned plasmonic nanopillars, nanowires, or both with an interparticle pitch ranging from ?/8?2?, where ? is the incident wavelength of light divided by the effective index of refraction of the sample; a coupled-plasmonic array sensor having vertically aligned periodic arrays of plasmonically coupled nanopillars, nanowires, or both with interparticle gaps sufficient to induce overlap between the plasmonic evanescent fields from neighboring nanoparticles, typically requiring edge-to-edge separations of less than 20 nm; and a plasmo-photonic array sensor having a double-resonant, periodic array of vertically aligned subarrays of 1 to 25 plasmonically coupled nanopillars, nanowires, or both where the subarrays are periodically spaced at a pitch on the order of a wavelength of light.

Abstract: A method of reversing Shockley stacking fault expansion includes providing a bipolar or a unipolar SiC device exhibiting forward voltage drift caused by Shockley stacking fault nucleation and expansion. The SiC device is heated to a temperature above 150° C. A current is passed via forward bias operation through the SiC device sufficient to induce at least a partial recovery of the forward bias drift.

Abstract: A method for reducing graphene film thickness on a donor substrate and transferring graphene films from a donor substrate to a handle substrate includes applying a bonding material to the graphene on the donor substrate, releasing the bonding material from the donor substrate thereby leaving graphene on the bonding material, applying the bonding material with graphene onto the handle substrate, and releasing the bonding material from the handle substrate thereby leaving the graphene on the handle substrate. The donor substrate may comprise SiC, metal foil or other graphene growth substrate, and the handle substrate may comprise a semiconductor or insulator crystal, semiconductor device, epitaxial layer, flexible substrate, metal film, or organic device.

Abstract: A method of reversing Shockley stacking fault expansion includes providing a bipolar or a unipolar SiC device exhibiting forward voltage drift caused by Shockley stacking fault nucleation and expansion. The SiC device is heated to a temperature above 150° C. A current is passed via forward bias operation through the SiC device sufficient to induce at least a partial recovery of the forward bias drift.

Abstract: A heterojunction between thin films of NCD and 4H—SiC was developed. Undoped and B-doped NCDs were deposited on both n? and p? SiC epilayers. I-V measurements on p+ NCD/n? SiC indicated Schottky rectifying behavior with a turn-on voltage of around 0.2 V. The current increased over eight orders of magnitude with an ideality factor of 1.17 at 30° C. Ideal energy-band diagrams suggested a possible conduction mechanism for electron transport from the SiC conduction band to either the valence band or acceptor level of the NCD film.