Method and device for cadmium-free solar cells
First Claim
1. A method for fabricating a thin film photovoltaic device free from cadmium comprising:
- providing a substrate having a thin film photovoltaic absorber with a surface region including a copper species, an indium species, a gallium species, a selenium species, and a sulfur species;
subjecting the surface region to a material containing at least a zinc species which is substantially free of cadmium;
heating at least the surface region to cause formation of zinc doped material at the surface region, wherein the heating comprises using a lamp heater to cause the surface region and adjacent regions to increase from room temperature to about 150 degrees Fahrenheit while keeping the majority of the absorber material substantially at room temperature;
forming zinc oxide over the zinc doped material; and
forming a transparent conductive material overlying the zinc oxide material.
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Accused Products
Abstract
A method for fabricating a thin film photovoltaic device is provided. The method includes providing a substrate comprising a thin film photovoltaic absorber which has a surface including copper, indium, gallium, selenium, and sulfur. The method further includes subjecting the surface to a material containing at least a zinc species substantially free of any cadmium. The surface is heated to cause formation of a zinc doped material. The zinc doped material is free from cadmium. Furthermore the method includes forming a zinc oxide material overlying the zinc doped material and forming a transparent conductive material overlying the zinc oxide material.
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Citations
19 Claims
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1. A method for fabricating a thin film photovoltaic device free from cadmium comprising:
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providing a substrate having a thin film photovoltaic absorber with a surface region including a copper species, an indium species, a gallium species, a selenium species, and a sulfur species; subjecting the surface region to a material containing at least a zinc species which is substantially free of cadmium; heating at least the surface region to cause formation of zinc doped material at the surface region, wherein the heating comprises using a lamp heater to cause the surface region and adjacent regions to increase from room temperature to about 150 degrees Fahrenheit while keeping the majority of the absorber material substantially at room temperature; forming zinc oxide over the zinc doped material; and forming a transparent conductive material overlying the zinc oxide material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14)
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10. A method for fabricating a thin film photovoltaic device free from cadmium comprising:
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providing a substrate having a thin film photovoltaic absorber with a surface region including a copper species, an indium species, a gallium species, a selenium species, and a sulfur species; subjecting the surface region to a material containing at least a zinc species which is substantially free of cadmium; heating at least the surface region to cause formation of zinc doped material at the surface region; forming zinc oxide over the zinc doped material, wherein formation comprises using a MOCVD process at a temperature between 150°
C. and 250°
C. without introducing dopant gas, and wherein the MOCVD process comprises using a work gas including water vapor, diethylzinc, and hydrogen sulfide to form a ZnO1-xSx material overlying the zinc-doped material; andforming a transparent conductive material overlying the zinc oxide material. - View Dependent Claims (11, 15, 16, 17, 18, 19)
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Specification