Georgia Tech Research Corporation

Other

Agilent Technologies, Inc.

Samsung Display Devices Co., Ltd.

Christopher J Summers

Zhong Lin Wang

Brent Karl Wagner

Wounjhang Park

Xudong Wang

Jeffrey Shaun King

Elton D Graugnard

Hisham Menkara

Kazuhito Yasuda

Youngrag Do

Hong Guen Yang

Janet Bee Yin Chua

William D Hunt

Young-Rag Do

Kevin F Brennan

Bee Yin Janet Chua

Do-hyung Park

Hong-geun Yang

Woun-jhang Park

Azlida Ahmad

A method of making nanostructures using a self-assembled monolayer of organic spheres is disclosed. The nanostructures include bowl-shaped structures and patterned elongated nanostructures. A bowl-shaped nanostructure with a nanorod grown from a conductive substrate through the bowl-shaped nanostructure may be configured as a field emitter or a vertical field effect transistor. A method of separating nanoparticles of a desired size employs an array of bowl-shaped structures.

Large scale patterned growth of aligned one-dimensional nanostructures

The present invention provides surface coated phosphors useful in field emission displays and vacuum fluorescent displays. The surface coated phosphor comprises a thin coating of rare earth oxide, e.g., yttrium oxide, disposed on an uncoated phosphor such as a sulfide phosphor. The present invention further provides a process for preparing a surface coated phosphor comprising contacting the uncoated phosphor with a rare earth hydroxide gel solution to obtain a rare earth hydroxide gel coated phosphor, drying the gel coated phosphor to remove solvent residues, and heat treating the dried rare earth hydroxide gel coated phosphor. The surface coated phosphors of the present invention have improved cathodoluminescence efficiency, coulombic aging resistance, chemical, and/or oxidative stability.

Rare earth oxide coated phosphors

A photonic crystal includes a phosphor matrix and a plurality of defect regions. The phosphor matrix defines a plurality of substantially spherical voids arranged in a triangular lattice arrangement. The phosphor matrix has a first index of refraction. The plurality of defect regions is distributed in a subset of the spherical voids. Each defect region has a second index of refraction that is different from the first index of refraction.

Photonic crystals

Methods of coating a semiconductor device with phosphor particles are disclosed. In the methods, a bath is provided which contains suspended particles of a first phosphor material and suspended particles of a second phosphor material. The particles of the first phosphor material have a mean particle size in the range from about 1 micron to about 6 microns, and the particles of the second phosphor material have a mean particle size in the range from about 12 microns to about 25 microns, wherein the particle size distribution of the phosphor material in the bath is bimodal. The semiconductor device is disposed in the bath containing the suspended particles, and a first biasing voltage is applied between an anode in electrical contact with the bath and the p side to hold the anode at a positive voltage with respect to the p side. A second biasing voltage is applied between the p side and the n side. In particular embodiments, the method results in a substantially conformal coating of the phosphor particles being deposited on at least one surface of the semiconductor structure.

Phosphor deposition methods

The present invention provides a process and apparatus for selectively depositing materials on a semiconductor device, such as depositing phosphors or other optical materials on a light emitting diode (LED), using an electrophoretic deposition process. The semiconductor device comprises a p-side and an n-side. A first biasing voltage is applied between an anode and the p-side of the semiconductor device. A second biasing voltage is applied between the p-side and the n-side of the semiconductor device. The relative biasing of the p-side and the n-side determines where coating is deposited on the semiconductor device. An optional pre-coating process is used to deposit a high resistivity dielectric material, such as silica, on the semiconductor device. The pre-coating can even the electric field on the surface of the semiconductor device, where local features such as metal connections or passivation layers disturb the electric field during phosphor deposition without pre-coating.

Electrophoretic processes for the selective deposition of materials on a semiconducting device

Rare earth oxide coated phosphors and a process for preparing the same

A method of producing two visible light photons from an oxide-based phosphor doped with praseodymium (Pr) and including atoms of at least one activator in response to excitation with a single ultraviolet light photon. The method includes exciting the Pr of the oxide-based phosphor with a photon of ultraviolet light to excite an electron to an excited state, the excited electron falling to a lower energy state in a non-radiative transition and transferring energy to excite a first activator atom in the oxide-based phosphor, the first activator atom emitting a first photon of visible light, and the excited electron falling further to a lower energy state in a non-radiative transition, transferring energy to excite a second activator atom in the oxide-based phosphor, the second activator atom emitting a second photon of visible light. An oxide-based phosphor doped with praseodymium includes atoms of at least one activator and emitting two visible light photons in response to excitation by a single ultraviolet light photon.

Oxide-based quantum cutter method and phosphor system

A low voltage tunnel thin film electroluminescent device (10) that comprises a conductive layer (13) that acts as a source of electrons, a first thin barrier layer (14) deposited on the conductive layer, a luminescent layer (16) deposited on the barrier layer a second thin barrier layer (14) deposited on said luminescent layer, and an electrode (18) deposited on the second barrier layer. Electrons from the source layer tunnel through the thin tunnel barrier layer into the luminescent layer which is doped with luminescent centers. The electrons that tunnel through the thin tunnel barrier layer into the luminescent layer have kinetic energy that is within a narrow energy distribution. The material comprising the first barrier layer is preferably chosen to have a positive conduction band off-set (22) with respect to the conductive layer and the material comprising the luminescent layer is chosen to have a negative conduction band off-set (24) with respect to said first barrier layer, wherein the negative conduction band off-set is greater than the positive conduction band off-set. Further, the different material layers are preferably lattice-matched and epitaxially grown in order to make the device more efficient.

Tunnel thin film electroluminescent device

An Acoustic Charge Transport Imager, suitable for use as a High Definition Television (HDTV) camera element, is disclosed in which an array of amorphous hydrogenated silicon based avalanche photodiodes are combined with acoustic charge transport channels in a GaAs substrate, to achieve very high speed read out of photogenerated charge. High speed read out allows the fabrication of detector arrays large enough to meet the resolution requirements of HDTV while ensuring operation within the timing constraints of the HDTV frame rate.

Acoustic charge transport imager

Growing community of inventors

Dunwoody, GA, United States of America

Christopher J Summers