Metal-doped Cu(In,Ga)(S,Se)2 Nanoparticles

Abstract

Various methods are used to provide a desired doping metal concentration in a CIGS-containing ink when the CIGS layer is deposited on a photovoltaic device. When the doping metal is antimony, it may be incorporated by: adding an antimony salt together with copper-, indium- and/or gallium-containing reagents at the beginning of the synthesis reaction of Cu(In,Ga)(S,Se) 2 nanoparticles; synthesizing Cu(In,Ga)(S,Se) 2 nanoparticles and adding an antimony salt to the reaction solution followed by mild heating before isolating the nanoparticles to aid antimony diffusion; and/or, using a ligand that is capable of capping the Cu(In,Ga)(S,Se) 2 nanoparticles with one end of its molecular chain and binding to antimony atoms with the other end of its chain.

What is claimed is: 
     
         1 . A process for preparing metal-doped nanocrystals comprising:
 adding an antimony salt to a mixture of copper-, indium-, and gallium-containing reagents at the beginning of a synthesis reaction of Cu(In,Ga)(S,Se) 2  nanoparticles.   
     
     
         2 . The process of  claim 1 , wherein the antimony salt is an antimony halide. 
     
     
         3 . The process of  claim 2 , wherein the antimony halide is antimony chloride. 
     
     
         4 . The process of  claim 2 , wherein the antimony halide is antimony fluoride. 
     
     
         5 . The process of  claim 2 , wherein the antimony halide is antimony iodide. 
     
     
         6 . The process of  claim 2 , wherein the antimony halide is antimony bromide. 
     
     
         7 . The process of  claim 1 , wherein the antimony salt is an organic antimony salt. 
     
     
         8 . The process of  claim 7 , wherein the organic antimony salt is antimony acetate. 
     
     
         9 . The process of  claim 7 , wherein the organic antimony salt is triphenylantimony. 
     
     
         10 . The process of  claim 7 , wherein the organic antimony salt is tris(dimethylamino)antimony. 
     
     
         11 . The process of  claim 7 , wherein the organic antimony salt is an antimony dialkyldithiocarbamate. 
     
     
         12 . The process of  claim 11 , wherein the antimony dialkyldithiocarbamate is antimony diethyldithiocarbamate. 
     
     
         13 . The process of  claim 11 , wherein the antimony dialkyldithiocarbamate is antimony dimethyldithiocarbamate. 
     
     
         14 . The process of  claim 11 , wherein the antimony dialkyldithiocarbamate is antimony methylhexyldithiocarbamate. 
     
     
         15 . The process of  claim 11 , wherein the antimony dialkyldithiocarbamate is antimony ethylhexyldithiocarbamate. 
     
     
         16 . A photovoltaic device comprising a layer of metal-doped nanocrystals prepared by the process of  claim 1 . 
     
     
         17 . An ink composition, the ink composition comprising:
 a solvent; and   metal-doped nanocrystals dispersed in the solvent, wherein the metal-doped nanocrystals are prepared by a process according to  claim 1 .   
     
     
         18 . A method of producing a film, the method comprising:
 printing an ink according to  claim 17  on a substrate; and   sintering the printed ink to coalesce the metal-doped nanocrystals and form a film on the substrate.