Xin Chen

US Patent:

6645656, Nov 11, 2003

Filed:

Mar 24, 2000

Appl. No.:

09/534385

Inventors:

Xin Chen - Houston TX
Naijuan Wu - Houston TX
Alex Ignatiev - Houston TX

Assignee:

University of Houston - Houston TX

International Classification:

H01M 810

US Classification:

429 32, 429 30, 429 33

Abstract:

A thin film solid oxide fuel cell (TFSOFC) having a porous metallic anode and a porous cathode is provided. The fuel cell is formed by using a continuous metal foil as a substrate to epitaxially deposit a thin film electrolyte on one surface of the foil. The metal foil may then be made porous by photolithographically patterning and etching the other surface of the foil to form holes extending through the foil to the electrolyte/foil interface. The cathode is then formed on the electrolyte by depositing a second thin film using known film deposition techniques. Further processing may be used to increase the porosity of the electrodes. The metal foil may be treated before film deposition to have an atomically ordered surface, which makes possible an atomically ordered thin film electrolyte.

US Patent:

7381492, Jun 3, 2008

Filed:

Nov 10, 2003

Appl. No.:

10/704725

Inventors:

Xin Chen - Houston TX, US
Naijuan Wu - Pearland TX, US
Alex Ignatiev - Houston TX, US

Assignee:

University of Houston - Houston TX

International Classification:

H01M 8/10
B05D 5/12

US Classification:

429 30, 427115

Abstract:

A thin film solid oxide fuel cell (TFSOFC) having a porous metallic anode and a porous cathode is provided. The fuel cell is formed by using a continuous metal foil as a substrate to epitaxially deposit a thin film electrolyte on one surface of the foil. The metal foil may then be made porous by photolithographically patterning and etching the other surface of the foil to form holes extending through the foil to the electrolyte/foil interface. The cathode is then formed on the electrolyte by depositing a second thin film using known film deposition techniques. Further processing may be used to increase the porosity of the electrodes. The metal foil may be treated before film deposition to have an atomically ordered surface, which makes possible an atomically ordered thin film electrolyte.

US Patent:

7510819, Mar 31, 2009

Filed:

May 18, 2006

Appl. No.:

11/436392

Inventors:

Xin Chen - Houston TX, US
Naijuan Wu - Houston TX, US
Alex Ignatiev - Houston TX, US
Yuxiang Zhou - Houston TX, US

Assignee:

Board of Regents, University of Houston - Houston TX

International Classification:

B05D 5/12
H01M 4/88

US Classification:

430320, 429100, 429159, 502101, 427115

Abstract:

A thin film solid oxide fuel cell (TFSOFC) having a porous metallic anode and a porous cathode is provided. The fuel cell is formed by using a continuous metal foil as a substrate onto which is deposited a thin anode metal layer which is then patterned to reveal an array of pores in the anode. A dense thin film electrolyte is then deposited onto the porous anode layer overcoating the anode and filling the anode pores. The substrate foil layer is then removed to allow for exposure of the porous anode/electrolyte to fuel. The cathode is then formed on the electrolyte by depositing a cathode thin film cap using known film deposition techniques. Further processing may be used to increase the porosity of the electrodes. The metal foil may be treated to have an atomically ordered surface, which makes possible an atomically ordered anode and atomically ordered thin film electrolyte for improved performance.

US Patent:

7608467, Oct 27, 2009

Filed:

Jan 13, 2005

Appl. No.:

11/034695

Inventors:

Naijuan Wu - Houston TX, US
Xin Chen - Houston TX, US
Alex Ignatiev - Houston TX, US

Assignee:

Board of Regents University of Houston - Houston TX

International Classification:

H01L 21/00
H01L 29/76

US Classification:

438 3, 257295

Abstract:

A switchable resistive device has a multi-layer thin film structure interposed between an upper conductive electrode and a lower conductive electrode. The multi-layer thin film structure comprises a perovskite layer with one buffer layer on one side of the perovskite layer, or a perovskite layer with buffer layers on both sides of the perovskite layer. Reversible resistance changes are induced in the device under applied electrical pulses. The resistance changes of the device are retained after applied electric pulses. The functions of the buffer layer(s) added to the device include magnification of the resistance switching region, reduction of the pulse voltage needed to switch the device, protection of the device from being damaged by a large pulse shock, improvement of the temperature and radiation properties, and increased stability of the device allowing for multivalued memory applications.

US Patent:

7955871, Jun 7, 2011

Filed:

Sep 17, 2009

Appl. No.:

12/586143

Inventors:

Naijuan Wu - Houston TX, US
Xin Chen - Houston TX, US
Alex Ignatiev - Houston TX, US

Assignee:

Board of Regents, University of Houston - Houston TX

International Classification:

H01L 21/00
H01L 29/76

US Classification:

438 3, 257295

Abstract:

A switchable resistive device has a multi-layer thin film structure interposed between an upper conductive electrode and a lower conductive electrode. The multi-layer thin film structure comprises a perovskite layer with one buffer layer on one side of the perovskite layer, or a perovskite layer with buffer layers on both sides of the perovskite layer. Reversible resistance changes are induced in the device under applied electrical pulses. The resistance changes of the device are retained after applied electric pulses. The functions of the buffer layer(s) added to the device include magnification of the resistance switching region, reduction of the pulse voltage needed to switch the device, protection of the device from being damaged by a large pulse shock, improvement of the temperature and radiation properties, and increased stability of the device allowing for multivalued memory applications.

US Patent:

8089111, Jan 3, 2012

Filed:

Sep 17, 2009

Appl. No.:

12/586147

Inventors:

Naijuan Wu - Houston TX, US
Xin Chen - Houston TX, US
Alex Ignatiev - Houston TX, US

Assignee:

Board of Regents, University of Houston - Houston TX

International Classification:

H01L 29/76
H01L 21/00

US Classification:

257295, 438 3

Abstract:

A switchable resistive device has a multi-layer thin film structure interposed between an upper conductive electrode and a lower conductive electrode. The multi-layer thin film structure comprises a perovskite layer with one buffer layer on one side of the perovskite layer, or a perovskite layer with buffer layers on both sides of the perovskite layer. Reversible resistance changes are induced in the device under applied electrical pulses. The resistance changes of the device are retained after applied electric pulses. The functions of the buffer layer(s) added to the device include magnification of the resistance switching region, reduction of the pulse voltage needed to switch the device, protection of the device from being damaged by a large pulse shock, improvement of the temperature and radiation properties, and increased stability of the device allowing for multivalued memory applications.

US Patent:

8409879, Apr 2, 2013

Filed:

May 23, 2011

Appl. No.:

13/068884

Inventors:

Naijuan Wu - Houston TX, US
Xin Chen - Houston TX, US
Alex Ignatiev - Houston TX, US

Assignee:

Board of Regents, University of Houston - Houston TX

International Classification:

H01L 21/00
H01L 21/02

US Classification:

438 3, 257295

Abstract:

A switchable resistive device has a multi-layer thin film structure interposed between an upper conductive electrode and a lower conductive electrode. The multi-layer thin film structure comprises a perovskite layer with one buffer layer on one side of the perovskite layer, or a perovskite layer with buffer layers on both sides of the perovskite layer. Reversible resistance changes are induced in the device under applied electrical pulses. The resistance changes of the device are retained after applied electric pulses. The selected duration of the electrical pulse is in the range of from about 8 nanosecond to about 100 milliseconds. The selected maximum value of the electrical pulse is in the range of from about 1 V to about 150 V. The electrical pulse may have square, saw-toothed, triangular, sine, oscillating or other waveforms, and may be of positive or negative polarity.

US Patent:

20040157747, Aug 12, 2004

Filed:

Feb 10, 2003

Appl. No.:

10/364908

Inventors:

Xin Chen - Houston TX, US
Naijuan Wu - Pearland TX, US
Alex Ignatiev - Houston TX, US
Yimin Chen - Bridgewater NJ, US

Assignee:

THE UNIVERSITY OF HOUSTON SYSTEM

International Classification:

B32B001/00
H01F006/00
H01B012/00
H01L039/00

US Classification:

505/238000

Abstract:

A thick atomically ordered single buffer layer for use in the integration of high temperature superconductor films with metallic substrates is disclosed. The buffer layer is a doped cerium oxide (CeO) material, where the doping reduces layer cracking through the modification of thermal expansion coefficient and film strain properties, while adjusting chemical properties and lattice parameters to better match those of the substrate and HTS layer.