Andrew J Tennant

US Patent:

54362040, Jul 25, 1995

Filed:

Aug 22, 1994

Appl. No.:

8/293826

Inventors:

David S. Albin - Denver CO
Jeffrey J. Carapella - Evergreen CO
John R. Tuttle - Denver CO
Miguel A. Contreras - Golden CO
Andrew M. Gabor - Boulder CO
Rommel Noufi - Golden CO
Andrew L. Tennant - Denver CO

Assignee:

Midwest Research Institute - Kansas City MO

International Classification:

H01L 21302

US Classification:

437225

Abstract:

A process for fabricating slightly Cu-poor thin-films of Cu(In,Ga)Se. sub. 2 on a substrate for semiconductor device applications includes the steps of forming initially a slightly Cu-rich, phase separated, mixture of Cu(In,Ga)Se. sub. 2 :Cu. sub. x Se on the substrate in solid form followed by exposure of the Cu(In,Ga)Se. sub. 2 :Cu. sub. x Se solid mixture to an overpressure of Se vapor and (In,Ga) vapor for deposition on the Cu(In,Ga)Se. sub. 2 :Cu. sub. x Se solid mixture while simultaneously increasing the temperature of the solid mixture toward a recrystallization temperature (about 550. degree. C. ) at which Cu(In,Ga)Se. sub. 2 is solid and Cu. sub. x Se is liquid. The (In,Ga) flux is terminated while the Se overpressure flux and the recrystallization temperature are maintained to recrystallize the Cu. sub. x Se with the (In, Ga) that was deposited during the temperature transition and with the Se vapor to form the thin-film of slightly Cu-poor Cu. sub. x (In,Ga). sub. y Se. sub. z. The initial Cu-rich, phase separated large grain mixture of Cu(In,Ga)Se. sub. 2 :Cu. sub.

US Patent:

57308527, Mar 24, 1998

Filed:

Dec 12, 1995

Appl. No.:

8/571150

Inventors:

Raghu N. Bhattacharya - Littleton CO
Miguel A. Contreras - Golden CO
James Keane - Lakewood CO
Andrew L. Tennant - Denver CO
John R. Tuttle - Denver CO
Kannan Ramanathan - Lakewood CO
Rommel Noufi - Golden CO

Assignee:

Davis, Joseph & Negley - Austin TX

International Classification:

H01L 3118
C23C 2802

US Classification:

205192

Abstract:

High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se. sub. 2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.

US Patent:

58040544, Sep 8, 1998

Filed:

Nov 26, 1997

Appl. No.:

8/979358

Inventors:

Raghu N. Bhattacharya - Littleton CO
Miguel A. Contreras - Golden CO
James Keane - Lakewood CO
Andrew L. Tennant - Denver CO
John R. Tuttle - Denver CO
Kannan Ramanathan - Lakewood CO
Rommel Noufi - Golden CO

Assignee:

Davis, Joseph & Negley - Austin TX

International Classification:

H01L 3118
C25D 356

US Classification:

205239

Abstract:

High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se. sub. 2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.

US Patent:

54418976, Aug 15, 1995

Filed:

Feb 16, 1994

Appl. No.:

8/197204

Inventors:

Rommel Noufi - Golden CO
Andrew M. Gabor - Boulder CO
John R. Tuttle - Denver CO
Andrew L. Tennant - Denver CO
Miguel A. Contreras - Golden CO
David S. Albin - Denver CO
Jeffrey J. Carapella - Evergreen CO

Assignee:

Midwest Research Institute - Kansas City MO

International Classification:

H01L 3118

US Classification:

437 5

Abstract:

A process for producing a slightly Cu-poor thin film of Cu(In,Ga)(Se,S). sub. 2 comprises depositing a first layer of (In,Ga). sub. x (Se,S). sub. y followed by depositing just enough Cu+(Se,S) or Cu. sub. x (Se,S) to produce the desired slightly Cu-poor material. In a variation, most, but not all, (about 90 to 99%) of the (In,Ga). sub. x (Se,S). sub. y is deposited first, followed by deposition of all the Cu+(Se,S) or Cu. sub. x (Se,S) to go near stoichiometric, possibly or even preferably slightly Cu-rich, and then in turn followed by deposition of the remainder (about 1 to 10%) of the (In,Ga). sub. x (Se,S). sub. y to end with a slightly Cu-poor composition. In yet another variation, a small portion (about 1 to 10%) of the (In,Ga). sub. x (Se,S). sub. y is first deposited as a seed layer, followed by deposition of all of the Cu+(Se,S) or Cu. sub. x (Se,S) to make a very Cu-rich mixture, and then followed deposition of the remainder of the (In,Ga). sub. x (Se,S). sub.