David J Randolph

US Patent:

20130037090, Feb 14, 2013

Filed:

Aug 10, 2011

Appl. No.:

13/207269

Inventors:

Santanu Bag - Yorktown Heights NY, US
David Aaron Randolph Barkhouse - New York NY, US
David Brian Mitzi - Mahopac NY, US
Teodor Krassimirov Todorov - Yorktown Heights NY, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

B05D 3/02
C23C 16/30
B05D 1/02
B05D 1/18
B05D 1/28
B05D 1/30
B05D 3/12
B05D 7/00
B05D 7/14
B05D 7/02
C23C 14/34
C23C 28/00
B32B 15/04
H01L 31/02
B05D 5/00

US Classification:

136252, 4273722, 4272481, 2041921, 205191, 428697, 428457

Abstract:

Techniques for fabrication of kesterite Cu—Zn—Sn—(Se,S) films and improved photovoltaic devices based on these films are provided. In one aspect, a method of fabricating a kesterite film having a formula CuZnSn(SSe), wherein 0≦x≦1; 0≦y≦1; 0≦z≦1; and −1≦q≦1 is provided. The method includes the following steps. A substrate is provided. A bulk precursor layer is formed on the substrate, the bulk precursor layer comprising Cu, Zn, Sn and at least one of S and Se. A capping layer is formed on the bulk precursor layer, the capping layer comprising at least one of Sn, S and Se. The bulk precursor layer and the capping layer are annealed under conditions sufficient to produce the kesterite film having values of x, y, z and q for any given part of the film that deviate from average values of x, y, z and q throughout the film by less than 20 percent.