FABRICATION OF IONIC LIQUID ELECTRODEPOSITED CU-SN-ZN-S-SE THIN FILMS AND METHOD OF MAKING
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.
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.