Techniques for enhancing performance of photovoltaic devices

摘要

Techniques for improving energy conversion efficiency in photovoltaic devices are provided. In one aspect, an antimony (Sb)-doped film represented by the formula, Cu1-yIn1-xGaxSbzSe2-wSw, provided, wherein: 0≦x≦1, and ranges therebetween; 0≦y≦0.2, and ranges therebetween; 0.001≦z≦0.02, and ranges therebetween; and 0≦w≦2, and ranges therebetween. A photovoltaic device incorporating the Sb-doped CIGS film and a method for fabrication thereof are also provided.

主权项

1. A method of fabricating a photovoltaic device, comprising the steps of:
providing a substrate; and forming an Sb-doped absorber layer formed on the substrate represented by a formula,
Cu1-yIn1-xGaxSbzSe2-wSw, wherein: 0≦x≦1, and ranges therebetween; 0≦y≦0.2, and ranges therebetween; 0.001≦z≦0.02, and ranges therebetween; 0≦w≦2, and ranges therebetween, wherein an amount of Sb in the absorber layer is from about 0.1 atomic percent to about 2 atomic percent of that of a sum of the In and the Ga, and wherein the absorber layer has a grain size of from about 0.2 μm to about two μm measured as a longest length of a grain from a cross-section of the absorber layer, and wherein the longest length of the grain from the cross-section of the film is greater than or equal to a thickness of the film; and performing a final anneal of the absorber layer at a temperature of from about 350° C. to about 375° C., wherein the step of forming the Sb-doped absorber layer further comprises the steps of: preparing an Sb-doped absorber layer precursor solution; spin-coating the Sb-doped absorber layer precursor solution onto the substrate; annealing the Sb-doped absorber precursor layer coated on the substrate, wherein the annealing step comprises an intermediate anneal that is configured to decompose the Sb-doped absorber precursor layer coated on the substrate; and repeating the spin-coating and annealing steps until a desired thickness for the Sb-doped absorber layer is achieved, wherein the spin-coating and annealing steps are all performed in-situ in a same inert atmosphere, in a same nitrogen-filled drybox, and wherein the step of preparing the Sb-doped absorber layer precursor solution, further comprises the step of: dissolving a Cu source, an In source, a Ga source, an Se source and an Sb source in hydrazine to produce one or more component solutions, wherein the Sb source is antimony trisulfide; and mixing two or more of the component solutions to form the Sb-doped absorber layer precursor solution.