Abstract:
A high efficiency light emitting diode (LED) comprised of a substrate, a buffer layer grown on the substrate (if such a layer is needed), a first active region comprising primary emitting species (PES) that are electrically-injected, a second active region comprising secondary emitting species (SES) that are optically-pumped by the light emitted from the PES, and photonic crystals, wherein the photonic crystals act as diffraction gratings to provide high light extraction efficiency, to provide efficient excitation of the SES, and/or to modulate the far-field emission pattern.
Abstract:
A high efficiency light emitting diode (LED) comprised of a substrate, a buffer layer grown on the substrate (if such a layer is needed), a first active region comprising primary emitting species (PES) that are electrically-injected, a second active region comprising secondary emitting species (SES) that are optically-pumped by the light emitted from the PES, and photonic crystals, wherein the photonic crystals act as diffraction gratings to provide high light extraction efficiency, to provide efficient excitation of the SES, and/or to modulate the far-field emission pattern.
Abstract:
A method for growing strain-engineered, self-assembled, semiconductor quantum dots (QDs) into ordered lattices. The nucleation and positioning of QDs into lattices is achieved using a periodic sub-surface lattice built-up on a substrate, stressor layer, and spacer layer. The unit cell dimensions, orientation and the number of QDs in the basis are tunable. Moreover, a 2D lattice can be replicated at periodic intervals along the growth direction to form a three-dimensional (3D) lattice of QDs.
Abstract:
Fabrication of metallic or non-metallic wires with nanometer widths and nanometer separation distances without the use of lithography. Wires are created in a two-step process involving forming the wires at the desired dimensions and transferring them to a planar substrate. The dimensions and separation of the wires are determined by the thicknesses of alternating layers of different materials that are in the form of a superlattice. Wires are created by evaporating the desired material onto the superlattice that has been selectively etched to provide height contrast between layers. The wires thus formed upon one set of superlattice layers are then transferred to a substrate.
Abstract:
Semiconductor devices having submonolayer superlattices are described. These devices may have periodic compositional variations in a direction parallel to the substrate surface as well as in the perpendicular direction. Such superlattices are useful in numerous types of devices including lasers, transistors, etc.
Abstract:
A method and resultant device, in which metal nanoparticles are self-assembled into two-dimensional lattices. A periodic hole pattern (wells) is fabricated on a photoresist substrate, the wells having an aspect ratio of less than 0.37. The nanoparticles are synthesized within inverse micelles of a polymer, preferably a block copolymer, and are self-assembled onto the photoresist nanopatterns. The nanoparticles are selectively positioned in the holes due to the capillary forces related to the pattern geometry, with a controllable number of particles per lattice point.
Abstract:
Fabrication of metallic or non-metallic wires with nanometer widths and nanometer separation distances without the use of lithography. Wires are created in a two-step process involving forming the wires at the desired dimensions and transferring them to a planar substrate. The dimensions and separation of the wires are determined by the thicknesses of alternating layers of different materials that are in the form of a superlattice. Wires are created by evaporating the desired material onto the superlattice that has been selectively etched to provide height contrast between layers. The wires thus formed upon one set of superlattice layers are then transferred to a substrate.
Abstract:
A method and device for converting light from a first wavelength to a second wavelength. The method comprises the steps of exciting an electron in a quantum dot with an incident infrared photon having the first wavelength, the excited electron having a first energy, tunneling the excited electron through a barrier into a stress induced quantum dot, and recombining the excited electron with a hole in the stress induced quantum dot, therein producing a photon having the second wavelength, typically in the visible range. The device comprises a substrate, a spacer layer, coupled to the substrate, a second layer, coupled to the spacer layer, wherein the second layer comprises a different material than the spacer layer, a third layer, coupled to the second layer, wherein the third layer comprises at least one quantum dot, a fourth layer, coupled to the third layer, comprising a quantum well corresponding to each quantum dot in the third layer, a fifth layer, coupled to the fourth layer, wherein the fourth layer and fifth layer comprise a strain induced quantum dot corresponding to each quantum dot in the third layer; and a sixth layer, coupled to the fifth layer, the substrate and the sixth layer for contacting the device.
Abstract:
Single GaAs quantum well or single GaAs active layer or single reverse interface structures with Al.sub.x Ga.sub.1-x As barrier layers have improved qualities when one or more narrow bandgap GaAs getter-smoothing layers, which are thin, are grown and are incorporated in the barrier layer before and in close proximity to the active layer.
Abstract translation:具有Al x Ga 1-x As阻挡层的单个GaAs量子阱或单个GaAs有源层或单个反向界面结构具有改进的质量,当薄的一个或多个窄带隙GaAs吸气剂平滑层生长并且被并入阻挡层之前和 靠近活动层。