Large scale chemical bath system and method for cadmium sulfide processing of thin film photovoltaic materials
First Claim
1. A method for forming a thin film photovoltaic material, the method comprising:
- providing a plurality of substrates, each of the substrates having a surface region, an overlying first electrode material, an absorber material including at least a copper species, an indium species, and a selenium species;
providing a chemical bath comprising an aqueous solution including a cadmium species, an ammonia species, and an organosulfur species, wherein the chemical bath is maintained at a pH of between about 11 and about 12;
immersing the plurality of substrates in the chemical bath;
maintaining the aqueous solution at a temperature ranging from about 50 to about 60 degrees Celsius during at least the immersing of the plurality of substrates;
while the substrates are immersed, forming a window material including at least cadmium sulfide to a thickness of about 200 Angstroms and less;
removing the plurality of substrates having at least the absorber material and the window layer from the aqueous solution;
subjecting the aqueous solution to a filter process to substantially remove particles greater than about 5 microns, the particles including colloids of cadmium sulfide; and
subjecting the plurality of substrates to a cleaning solution.
4 Assignments
0 Petitions
Accused Products
Abstract
A method for forming a thin film photovoltaic material. The method includes providing a plurality of substrates. Each of the substrates has a surface region, an overlying first electrode material, an absorber material including at least a copper species, an indium species, and a selenium species. The method immerses the plurality of substrates in an aqueous solution including an ammonia species, a cadmium species, and a organosulfur (for example, thiourea) species in a bath to form a cadmium sulfide window material having a thickness of less than about 200 Angstroms overlying the absorber material. The aqueous solution is maintained at a temperature ranging from about 50 to about 60 Degrees Celsius. The plurality of substrates having at least the absorber material and the window layer are removed from the aqueous solution. The aqueous solution is further subjected to a filter process to substantially remove one or more particles greater than about 5 microns.
264 Citations
16 Claims
-
1. A method for forming a thin film photovoltaic material, the method comprising:
-
providing a plurality of substrates, each of the substrates having a surface region, an overlying first electrode material, an absorber material including at least a copper species, an indium species, and a selenium species; providing a chemical bath comprising an aqueous solution including a cadmium species, an ammonia species, and an organosulfur species, wherein the chemical bath is maintained at a pH of between about 11 and about 12; immersing the plurality of substrates in the chemical bath; maintaining the aqueous solution at a temperature ranging from about 50 to about 60 degrees Celsius during at least the immersing of the plurality of substrates; while the substrates are immersed, forming a window material including at least cadmium sulfide to a thickness of about 200 Angstroms and less; removing the plurality of substrates having at least the absorber material and the window layer from the aqueous solution; subjecting the aqueous solution to a filter process to substantially remove particles greater than about 5 microns, the particles including colloids of cadmium sulfide; and subjecting the plurality of substrates to a cleaning solution. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. A method for forming a thin film photovoltaic material, the method comprising:
-
providing a plurality of substrates, each of the substrates having a surface region, an overlying first electrode material, an absorber material including at least a copper species, an indium species, and a selenium species; providing a chemical bath comprising an aqueous solution including an ammonia species, a cadmium species, and thiourea, wherein the chemical bath is maintained at a pH of between about 11 and about 12; immersing the plurality of substrates in the chemical bath; maintaining the aqueous solution at a temperature ranging from about 50 to about 60 degrees Celsius during at least the immersing of the plurality of substrates; while the substrates are immersed, forming a window material including at least cadmium sulfide to a thickness of about 200 Angstroms and less; removing the plurality of substrates having at least the absorber material and the window layer from the aqueous solution; subjecting the aqueous solution to a filter process to substantially remove one or more particles greater than about 5 microns, the one or more particles including colloids of cadmium sulfide; subjecting the plurality of substrates to a cleaning solution; drying the plurality of substrates; and maintaining the plurality of substrates in a dry environment to maintain at least the absorber layer substantially free from moisture from water vapor.
-
Specification