David Y Hsu

20020042241, Apr 11, 2002

Dec 12, 2001

10/012615

David Hsu - Alexandria VA, US

H01J009/24

445/024000

A field emitter cell includes a thin-film-edge emitter normal to the gate layer. The field emitter cell may include a conductive substrate layer, an insulator layer having a perforation, a gate layer having a perforation, an emitter layer, and other optional layers. The perforation in the gate layer is larger and concentrically offset with respect to the perforation in the insulating layer and may be of a tapered construction. Alternatively, the perforation in the gate layer may be coincident with, or larger or smaller than, the perforation in the insulating layer, provided that the gate layer is shielded from the emitter from a direct line-of-sight by a nonconducting standoff layer. Optionally, the thin-film-edge emitter may include incorporated nanofilaments. The field emitter cell has low gate current, making it useful for various applications such as field emitter displays, high voltage power switching, microwave, RF amplification and other applications that require high emission currents.

20020055319, May 9, 2002

Dec 12, 2001

10/012612

David Hsu - Alexandria VA, US

H01J009/24

445/024000

A field emitter cell includes a thin-film-edge emitter normal to the gate layer. The field emitter cell may include a conductive substrate layer, an insulator layer having a perforation, a gate layer having a perforation, an emitter layer, and other optional layers. The perforation in the gate layer is larger and concentrically offset with respect to the perforation in the insulating layer and may be of a tapered construction. Alternatively, the perforation in the gate layer may be coincident with, or larger or smaller than, the perforation in the insulating layer, provided that the gate layer is shielded from the emitter from a direct line-of-sight by a nonconducting standoff layer. Optionally, the thin-film-edge emitter may include incorporated nanofilaments. The field emitter cell has low gate current, making it useful for various applications such as field emitter displays, high voltage power switching, microwave, RF amplification and other applications that require high emission currents.

20020081373, Jun 27, 2002

Mar 6, 2002

10/090630

David Hsu - Alexandria VA, US
Yongchi Tian - Princeton NJ, US

B05D005/12
B05D005/06
B05D003/02
B05D001/36

427/064000, 427/372200, 427/402000

Doped phosphors (e.g., metal orthosilicates) are made by adding solid particulate precursor to a solution of an alkoxide precursor and a dopant precursor before hydrolysis is allowed to occur. The mixture is then allowed to hydrolyze, resulting in a sol-gel condensation reaction. The solid particulate precursor can be fumed silica, and acts as a nucleation site for the sol-gel reaction product. After the sol-gel reaction, the mixture is dried and fired to form phosphors. The phosphors are especially suitable for applications in which there is low voltage operation.

20020125805, Sep 12, 2002

Mar 9, 2001

09/804641

David Hsu - Alexandria VA, US

H01J001/16

313/309000, 313/351000, 313/336000

The present invention discloses a new field emitter cell and array consisting of groups of nanofilaments forming emitter cathodes. Control gates are microprocessed to be integrally formed with groups of nanofilament emitter cathodes on a substrate. Groups of nanofilaments are grown directly on the substrate material. As a result, the control gates and groups of nanofilaments are self-aligned with one another.

20020190622, Dec 19, 2002

Jun 13, 2001

09/883458

David Hsu - Alexandria VA, US
Henry Gray - Alexandria VA, US
Joan Gray - Alexandria VA, US
James Gray - , US

H01J001/304
H01J019/24

313/309000

A field emitter cell includes a thin film edge emitter normal to a gate layer. The field emitter is a multilayer structure including a low work function material sandwiched between two protective layers. The field emitter may be fabricated from a composite starting structure including a conductive substrate layer, an insulation layer, a standoff layer and a gate layer, with a perforation extending from the gate layer into the substrate layer. The emitter material is conformally deposited by chemical beam deposition along the sidewalls of the perforation. Alternatively, the starting material may be a conductive substrate having a protrusion thereon. The emitter layer, standoff layer, insulation layer, and gate layer are sequentially deposited, and the unwanted portions of each are preferentially removed to provide the desired structure.

20030132714, Jul 17, 2003

Jan 13, 2003

10/340669

Jonathan Shaw - Springfield VA, US
David Hsu - Alexandria VA, US

H05B039/00

315/169300, 315/160000

An apparatus and method for regulating the emission current from a single (macroscopic) field emitter, from groups of emitters within a large (microscopic) array, or from each cell within an array is described. The apparatus includes an additional aperture, fabricated at each field emitter array cell, to create and electron energy filter. The filter aperture of the electron energy filter is similar to the gate aperture but located above or in front of the gate aperture, and is held at a positive potential lower than the gate. The filter allows only those electrons with energy greater than some minimum (the cutoff energy) to pass through. A current-limiting circuit is placed in series with the gate aperture, limiting the total current of electrons that do not pass through the filter. Thus, emission from low energy states is limited without limiting emission from states near the Fermi level.

20040108804, Jun 10, 2004

Apr 15, 2003

10/414573

David Hsu - Alexandria VA, US

H01J001/62
H01J063/04

313/495000

A field emitter cell includes a thin-film-edge emitter normal to the gate layer. The field emitter cell may include a conductive substrate layer, an insulator layer having a perforation, a gate layer having a perforation, an emitter layer, and other optional layers. The perforation in the gate layer is larger and concentrically offset with respect to the perforation in the insulating layer and may be of a tapered construction. Alternatively, the perforation in the gate layer may be coincident with, or larger or smaller than, the perforation in the insulating layer, provided that the gate layer is shielded from the emitter from a direct line-of-sight by a nonconducting standoff layer. Optionally, the thin-film-edge emitter may include incorporated nanofilaments. The field emitter cell has low gate current making it useful for various applications such as field emitter displays, high voltage power switching, microwave, RF amplification and other applications that require high emission currents.

20070284631, Dec 13, 2007

Jun 9, 2006

11/452567

David S.Y. Hsu - Alexandria VA, US
Jonathan L. Show - Springfield VA, US

H01L 29/76
H01L 29/94
H01L 31/00

257288

A field ionization device can include a first insulator layer on a first side of a substrate, a conductive gate layer on the first insulator layer, a cavity in the substrate, a portion of first insulator over the cavity, an aperture in the portion of the first insulator layer and the conductive gate layer thereby forming an aperture and aperture sidewall. The device can include a second insulator layer on the aperture sidewall and surface of the cavity, a metallization layer over the second insulator layer, a catalyst layer on the metallization layer, and a carbon nanotube. The cavity can be made by etching a second side of the substrate to near the insulator layer, wherein the second side is opposite the first side. The carbon nanotube can be grown from the catalyst layer. The device can further include a collector located near the carbon nanotube. The conductive gate layer can be biased negative with respect to the carbon nanotube. An electric field can exist between the carbon nanotube and the conductive gate layer. Another embodiment can include an array of multiple devices as described herein wherein the multiple devices are in close proximity to each other. Also provided is a method of making the device.