Fabrication of ionic liquid electrodeposited cu-sn-zn-s-se thin films and method of making

Abstract

A semiconductor thin-film and method for producing a semiconductor thin-films comprising a metallic salt, an ionic compound in a non-aqueous solution mixed with a solvent and processing the stacked layer in chalcogen that results in a CZTS/CZTSS thin films that may be deposited on a substrate is disclosed.

We claim: 
     
         1 . A semiconductor thin-film comprising:
 a substrate;   a first layer deposited onto the substrate, comprising a metallic salt;   a second layer deposited onto the first layer, comprising a metallic salt; and   a third layer deposited onto the second layer, comprising an ionic compound in a non-aqueous solution mixed with a solvent, wherein the first, second and third layers are stacked and annealed in chalcogen.   
     
     
         2 . The semiconductor thin-film according to  claim 1 , wherein the metallic salt consists of a group selected from copper sulfate, stannous chloride (SnCl 2 ), stannic chloride (SnCl 4 ), zinc sulfate, or zinc chloride. 
     
     
         3 . The semiconductor thin-film according to  claim 1 , wherein the chalcogen is selected from a group consisting of selenium, sulfur, telluride or polonium. 
     
     
         4 . The semiconductor thin-film according to  claim 1 , wherein the ionic compound is selected from a group consisting of sodium sulfate, sodium fluoride, potassium fluoride, potassium bifluoride, sodium bifluoride, sodium chloride, zinc chloride, or potassium chloride. 
     
     
         5 . The semiconductor thin-film according to  claim 1 , wherein the ionic compound comprises choline chloride (C 5 H 14 ClNO). 
     
     
         6 . The semiconductor thin-film according to  claim 1 , wherein the solvent comprises ethylene glycol mixed with the ionic compound. 
     
     
         7 . The semiconductor thin-film according to  claim 1 , wherein the solvent comprises water, HCl or boric acid (H 3 BO 3 ). 
     
     
         8 . The semiconductor thin-film according to  claim 1 , wherein the ionic compound comprises sulfonate. 
     
     
         9 . The semiconductor thin-film according to  claim 1 , wherein the solvent comprises a surfactant mixed with the ionic compound. 
     
     
         10 . The semiconductor thin-film according to  claim 1 , wherein the sulfonate is selected from a group consisting of mesylate, triflate, tosylate, or besylate. 
     
     
         11 . A method for producing a semiconductor thin-film comprising the steps of:
 (a) electrodepositing a first layer of a metallic salt from an aqueous bath onto a substrate;   (b) electrodepositing a second layer comprising a metallic salt onto the first layer;   (c) electrodepositing a third layer comprising an ionic compound in a non-aqueous solution mixed with a solvent onto the second layer; and   (d) annealing the first, second and third stacked layers in chalcogen.   
     
     
         12 . The method of  claim 11 , wherein the metallic salt is selected from a group consisting of copper sulfate, stannous chloride (SnCl 2 ), stannic chloride (SnCl 4 ), zinc sulfate, or zinc chloride. 
     
     
         13 . The method of  claim 11 , wherein the chalcogen is selected from a group consisting of selenium, sulfur, telluride or polonium. 
     
     
         14 . The method of  claim 11 , wherein the ionic compound is selected from a group consisting of sodium sulfate, sodium fluoride, potassium fluoride, potassium bifluoride, sodium bifluoride, sodium chloride, zinc chloride, or potassium chloride. 
     
     
         15 . The method of  claim 11 , wherein the ionic compound comprises choline chloride (C 5 H 14 ClNO). 
     
     
         16 . The method of  claim 15 , wherein the solvent comprises ethylene glycol mixed with the ionic compound. 
     
     
         17 . The method of  claim 11 , wherein the solvent comprises water, HCl or boric acid (H 3 BO 3 ). 
     
     
         18 . The method of  claim 11 , wherein the ionic compound comprises sulfonate. 
     
     
         19 . The method of  claim 18 , wherein the solvent comprises a surfactant mixed with the ionic compound. 
     
     
         20 . The method of  claim 18 , wherein the sulfonate is selected from a group consisting of mesylate, triflate, tosylate, or besylate. 
     
     
         21 . The method of  claim 11 , wherein the semiconductor thin-film is deposited on a substrate comprising at least one copper salt. 
     
     
         22 . The method of  claim 11 , wherein the semiconductor thin-film is deposited on a substrate comprising at least one tin salt. 
     
     
         23 . The method of  claim 11 , wherein the semiconductor thin-film is deposited on a substrate comprising at least one zinc salt. 
     
     
         24 . The method of  claim 11 , further comprising a plating current density in the range of approximately 1 to 8 mA/cm 2 . 
     
     
         25 . The method of  claim 11 , wherein the substrate is selected from a group consisting of glass, chromium, molybdenum, silicon, silicon dioxide, aluminum oxide, sapphire, germanium, an alloy of silicon and germanium, indium phosphide (InP) or any combination thereof. 
     
     
         26 . The method of  claim 11 , wherein the substrate comprises glass coated with a Molybdenum film. 
     
     
         27 . The method of  claim 11 , wherein the electroplating solution comprises a pH in the range of approximately 1-5.