摘要:
A cold electron emitter may include a heavily a p-doped semiconductor, and dielectric layer, and a metallic layer (p-D-M structure). A modification of this structure includes a heavily n+ doped region below the p region (n+-p-D-M structure). These structures make it possible to combine high current emission with stable (durable) operation. The high current density is possible since under certain voltage drop across the dielectric layer, effective negative electron affinity is realized for the quasi-equilibrium “cold” electrons accumulated in the depletion layer in the p-region next to the dielectric layer. These electrons are generated as a result of the avalanche in the p-D-M structure or injection processes in the n+-p-D-M structure. These emitters are stable since they make use of relatively low extracting field in the vacuum region and are not affected by contamination and absorption from accelerated ions. In addition, the structures may be fabricated with current state-of-the-art technology.
摘要:
A cold electron emitter may include a heavily n+ doped wide band gap (WBG) substrate, a p-doped WBG region, and a low work function metallic layer (n+-p-M structure). A modification of this structure includes heavily p+ doped region between p region and M metallic layer (n+-p-p+-M structure). These structures make it possible to combine high current emission with stable (durable) operation. The high current density is possible because the p-doped (or p+ heavily doped) WBG region acts as a negative electron affinity material when in contact with low work function metals. The injection emitters with the n+-p-M and n+-p-p+-M structures are stable since the emitters make use of relatively low extracting electric field and are not affected by contamination and/or absorption from accelerated ions. In addition, the structures may be fabricated with current state-of-the-art technology.
摘要:
A magnetic sensor based on efficient spin injection of spin-polarized electrons from ferromagnets into semiconductors and rotation of electron spin under a magnetic field. Previous spin injection structures suffered from very low efficiency (less than 5%). A spin injection device with a semiconductor layer sandwiched between &dgr;-doped layers and ferromagnets allows for very high efficient (close to 100%) spin polarization to be achieved at room temperature, and allows for high magneto-sensitivity and very high operating speed, which in turn allows devising ultra fast and sensitive magnetic sensors.
摘要:
A dynamic optical crossbar array includes a first set of parallel transparent electrode lines, a bottom set of parallel electrode lines that cross said transparent electrode lines, and an optically variable material disposed between said first set of transparent electrode lines and said bottom set of electrode lines.
摘要:
A negative index material (or metamaterial) crossbar includes a first layer of approximately parallel nanowires and a second layer of approximately parallel nanowires that overlay the nanowires in the first layer. The nanowires in the first layer are approximately perpendicular in orientation to the nanowires in the second layer. Each nanowire of the first layer and each nanowire of the second layer has substantially regularly spaced fingers. The crossbar further includes resonant elements at nanowire intersections between the respective layers. Each resonant element includes two fingers of a nanowire in the first layer and two fingers of a nanowire in the second layer.
摘要:
A holographic mirror 10 for re-directing an optical signal that includes a base 14 having an outer surface 16, and a plurality of discrete nano-structures 12 formed into the outer surface of the base. Each nano-structure has an out-of-plane dimension 20 that is within an order of magnitude of one or both in-plane dimensions 22. The plurality of nano-structures are configured in a repeating pattern with a predetermined spacing 18 between nano-structures for re-directing an optical signal.
摘要:
An apparatus for performing a sensing application includes a reservoir to contain a solution, a dispenser to dispense the solution from the reservoir, and a substrate having a plurality of nano-fingers positioned to receive the dispensed solution, in which the plurality of nano-fingers are flexible, such that the plurality of nano-fingers are configurable with respect to each other. The apparatus also includes an illumination source to illuminate the received solution, an analyte introduced around the plurality of nano-fingers, and the plurality of nano-fingers, in which light is to be emitted from the analyte in response to being illuminated. The apparatus further includes a detector to detect the light emitted from the analyte.
摘要:
An apparatus for surface enhanced Raman spectroscopy includes a substrate, a nanostructure and a plasmonic material. The nanostructure and the plasmonic material are integrated together to provide electronic and plasmonic enhancement to a Raman signal produced by electromagnetic radiation scattering from an analyte.
摘要:
A sensor for surface enhanced Raman spectroscopy (SERS) sensor includes surfaces and an actuator to adjust an intersurface spacing between the surfaces to contain an analyte and allow the analyte to be released from containment.
摘要:
An electrically driven device for surface enhanced Raman spectroscopy includes a first electrode, a substrate positioned proximate to the first electrode, a plurality of cone shaped protrusions formed integrally with or on a substrate surface, a Raman signal-enhancing material coated on each protrusion, and a second electrode positioned relative to the first electrode at a predetermined distance. Each of the protrusions has a tip with a radius of curvature ranging from about 0.1 nm to about 100 nm. The second electrode is positioned relative to the first electrode such that the electrodes together produce an electric field when a voltage bias is applied therebetween. The electric field has a field distribution that creates a stronger field gradient at a region proximate to the tips than at other portions of the substrate.