David J Ford

US Patent:

6362021, Mar 26, 2002

Filed:

Feb 2, 2001

Appl. No.:

09/776514

Inventors:

David H. Ford - Wilmington DE
Allen M. Barnett - Newark DE
Robert B. Hall - Newark DE
James A. Rand - Landenberg PA

Assignee:

AstroPower, Inc. - Newark DE

International Classification:

H01L 31068

US Classification:

438 97, 136258, 136256, 136261, 257 64, 257461, 257465, 257459, 257431, 427588, 427578, 427 74, 427 58, 438488, 438166, 438487, 423348

Abstract:

A polycrystalline film of silicon including silicon grains having an aspect ratio, d/t, of more than 1:1, wherein âdâ is the grain diameter and âtâ is the grain thickness. The polycrystalline film of silicon can be used to form an electronic device, such as a monolithically integrated solar cell having ohmic contacts formed on opposed surfaces or on the same surface of the film. A plurality of solar cells can be monolithically integrated to provide a solar cell module that includes an electrically insulating substrate and at least two solar cells disposed on the substrate in physical isolation from one another. Methods for manufacturing the film, solar cell and solar cell module are also disclosed. The simplified structure and method allow for substantial cost reduction on a mass-production scale, at least in part due to the high aspect ratio silicon grains in the film.

US Patent:

6420643, Jul 16, 2002

Filed:

Feb 2, 2001

Appl. No.:

09/776583

Inventors:

David H. Ford - Wilmington DE
Allen M. Barnett - Newark DE
Robert B. Hall - Newark DE
James A. Rand - Landenberg PA

Assignee:

AstroPower, Inc. - Newark DE

International Classification:

H01L 31042

US Classification:

136244, 136249, 136251, 136255, 136256, 136261, 136252, 257433, 257461, 257443, 257454, 257457, 257459

Abstract:

A polycrystalline film of silicon including silicon grains having an aspect ratio, d/t, of more than 1:1, wherein âdâ is the grain diameter and âtâ is the grain thickness. The polycrystalline film of silicon can be used to form an electronic device, such as a monolithically integrated solar cell having ohmic contacts formed on opposed surfaces or on the same surface of the film. A plurality of solar cells can be monolithically integrated to provide a solar cell module that includes an electrically insulating substrate and at least two solar cells disposed on the substrate in physical isolation from one another. Methods for manufacturing the film, solar cell and solar cell module are also disclosed. The simplified structure and method allow for substantial cost reduction on a mass-production scale, at least in part due to the high aspect ratio silicon grains in the film.

US Patent:

20100059107, Mar 11, 2010

Filed:

Jul 31, 2006

Appl. No.:

12/066960

Inventors:

Allen M. Barnett - Landenberg PA, US
Jerome S. Culik - Nottingham PA, US
David H. Ford - Elkton MD, US

Assignee:

BLUE SQUARE ENERGY INCORPORATED - North East MD

International Classification:

H01L 31/00
H01L 21/027
H01L 31/18

US Classification:

136255, 438 72, 136256, 257E31002, 257E21023

Abstract:

A front-surface-illuminated photovoltaic device, having a first semiconductor layer () with a back surface, a second semiconductor layer () with a front surface, the second layer () having the opposite doping type to the first layer () and deposited on the first layer (); and at least one ohmic contact () to each of the first () and second () semiconductor layers; and a process for making the photovoltaic device. The device may also have a barrier layer () for reducing diffusion of impurities from the first semiconductor layer () into the second semiconductor layer (), a blocking layer (), and a reflector layer (). The device may have an array of first regions () in which the second layer () is of opposite doping type to that of the first layer () and forms p-n junctions () in these first regions (), and second regions (), each second region () containing the barrier layer () and the reflector layer (). The first () and second () regions are laterally intermixed, have a lateral shape of either bounded regions or stripes, or a combination of bounded regions and stripes.

US Patent:

54964164, Mar 5, 1996

Filed:

Aug 5, 1994

Appl. No.:

8/286673

Inventors:

Robert B. Hall - Newark DE
Allen M. Barnett - Newark DE
Sandra R. Collins - Chesapeake City MD
Joseph C. Checchi - Newark DE
David H. Ford - Wilmington DE
Christopher L. Kendall - Wilmington DE
Steven M. Lampo - Elkton MD
James A. Rand - Oxford PA

Assignee:

Astropower, Inc. - Newark DE

International Classification:

H10L 310392
H10L 310368
H10L 3118

US Classification:

136258

Abstract:

The invention relates to techniques for manufacturing columnar-grained polycrystalline sheets which have particular utility as substrates or wafers for solar cells. The sheet is made by applying granular silicon to a setter material which supports the granular material. The setter material and granular silicon are subjected to a thermal profile all of which promote columnar growth by melting the silicon from the top downwardly. The thermal profile sequentially creates a melt region at the top of the granular silicon and then a growth region where both liquid and a growing polycrystalline sheet layer coexist. An annealing region is created where the temperature of the grown polycrystalline silicon sheet layer is controllably reduced to effect stress relief.

US Patent:

RE361569, Mar 23, 1999

Filed:

Jan 24, 1997

Appl. No.:

8/788660

Inventors:

Robert B. Hall - Newark DE
Allen M. Barnett - Newark DE
Sandra R. Collins - Chesapeake City MD
Joseph C. Checchi - Newark DE
David H. Ford - Wilmington DE
Christopher L. Kendall - Wilmington DE
Steven M. Lampo - Elkton MD
James A. Rand - Oxford PA

Assignee:

Astropower, Inc. - Newark DE

International Classification:

H01L 310392
H01L 310368
H01L 3118

US Classification:

136258

Abstract:

The invention relates to techniques for manufacturing columnar-grained polycrystalline sheets which have particular utility as substrates or wafers for solar cells. The sheet is made by applying granular silicon to a setter material which supports the granular material. The setter material and granular silicon are subjected to a thermal profile all of which promote columnar growth by melting the silicon from the top downwardly. The thermal profile sequentially creates a melt region at the top of the granular silicon and then a growth region where both liquid and a growing polycrystalline sheet layer coexist. An annealing region is created where the temperature of the grown polycrystalline silicon sheet layer is controllably reduced to effect stress relief.

US Patent:

62078917, Mar 27, 2001

Filed:

Feb 1, 2000

Appl. No.:

9/495853

Inventors:

Robert B. Hall - Newark DE
Allen M. Barnett - Newark DE
Joseph C. Checchi - Newark DE
David H. Ford - Wilmington DE
Christopher L. Kendall - Hockessin DE
James A Rand - Landenberg PA

Assignee:

Astropower, Inc. - Newark DE

International Classification:

H01L31/00

US Classification:

136258PC

Abstract:

The invention relates to a silicon sheet having columnar grains extending axially through the sheet from one free surface of the sheet to the other free surface. The sheet has an electrical resistivity in the range of 0. 1 to 10 ohm-cm.

US Patent:

50571630, Oct 15, 1991

Filed:

May 4, 1988

Appl. No.:

7/190138

Inventors:

Allen M. Barnett - Newark DE
Robert B. Hall - Newark DE
James A. Rand - Oxford PA
David H. Ford - Wilmington DE

Assignee:

AstroPower, Inc. - Newark DE

International Classification:

H01L 3106

US Classification:

136258

Abstract:

A thin-film photovoltaic solar cell features a thin polycrystalline silicon active semiconductor formed over a conductive ceramic substrate. Between the substrate and the adjacent active semiconductor layer is a barrier layer which provides for reflection of light, minimizes back surface recombination and prevents contamination of the active semiconductor.

US Patent:

53363353, Aug 9, 1994

Filed:

Oct 9, 1992

Appl. No.:

7/959009

Inventors:

Robert B. Hall - Newark DE
Allen M. Barnett - Newark DE
Jacob E. Brown - Newark DE
Joseph C. Checchi - Newark DE
David H. Ford - Wilmington DE
Christopher L. Kendall - Wilmington DE
William P. Mulligan - Hockessin DE
James A. Rand - Oxford PA
Todd R. Ruffins - Newark DE

Assignee:

AstroPower, Inc. - Newark DE

International Classification:

H01L 310392
H01L 310368
H01L 3118

US Classification:

136258

Abstract:

The invention relates to techniques for manufacturing columnar-grained polycrystalline sheets which have particular utility as substrates or wafers for solar cells. The sheet is made by applying granular silicon to a setter material which supports the granular material. The setter material and granular silicon are subjected to a thermal profile all of which promote columnar growth by melting the silicon from the top downwardly. The thermal profile sequentially creates a melt region at the top of the granular silicon and then a growth region where both liquid and a growing polycrystalline sheet layer coexist. An annealing region is created where the temperature of the grown polycrystalline silicon sheet layer is controllably reduced to effect stress relief.