Mahaprasad Kar

US Patent:

20140014525, Jan 16, 2014

Filed:

Jul 12, 2013

Appl. No.:

13/940924

Inventors:

Neal Donald McDaniel - Bartlesville OK, US
Mahaprasad Kar - Bartlesville OK, US
Dennis Schultz - Bartlesville OK, US
Bruce B. Randolph - Bartlesville OK, US

Assignee:

Phillips 66 Company - Houston TX

International Classification:

C25B 1/02

US Classification:

205342

Abstract:

A method is taught of introducing an alternating voltage between a first electrode and a second electrode in a mixture comprising a depolarizing agent. The method then alternates between forming hydrogen gas at the first electrode while simultaneously oxidizing a depolarizing agent at the second electrode and forming hydrogen gas at the second electrode while simultaneously oxidizing the depolarizing agent at the first electrode.

US Patent:

20120115312, May 10, 2012

Filed:

May 26, 2010

Appl. No.:

13/321834

Inventors:

Rakesh Agrawal - West Lafayette IN, US
Hugh W. Hillhouse - Seattle WA, US
Qijie Guo - West Lafayette IN, US
Mahaprasad Kar - Bartlesville OK, US

Assignee:

PURDUE RESEARCH FOUNDATION - West Lafayette IN

International Classification:

H01L 21/20

US Classification:

438478, 257E2109

Abstract:

In one aspect, a method for forming CIGSSe-based thin films includes depositing at least two layers of particles on a substrate. At least one layer includes a CIGSSe particle having a chemical composition denoted by Cu(InI-xGax)(S1-ySey)2 where 0≦x ≦1 and 0≦y≦1. The particle layers are annealed individually or in combination to form a CIGSSe thin film having a composition profile along the depth of the film In addition, one or more of the particle layers may be also deposited on a pre-existing absorber and annealed to form a film having a composition profile along the depth of the film After depositing thin film precursor layers containing CIGSSe nanoparticles (and/or any other particles) on a suitable substrate in accordance with a desired concentration profile, a subsequent treatment under an Se and/or S containing atmosphere at elevated temperature may be used to convert the precursor layers into a CIGSSe absorber film In a further aspect, a method for forming multinary metal chalcogenide semiconductor layers directly on a substrate from a solution of precursors, includes depositing a plurality of metal chalcogenide particles onto a substrate to form a precursor film A species containing a metal, chalcogen, or combination thereof is dissolved in a solution containing one or more solvents to form a liquid chalcogen medium. The precursor film is contacted with the liquid chalcogen medium at a temperature of at least 50 C to form a multinary metal chalcogenide thin film