Growth of antimony doped P-type zinc oxide nanowires for optoelectronics
In a method of growing p-type nanowires, a nanowire growth solution of zinc nitrate (Zn(NO 3 ) 2 ), hexamethylenetetramine (HMTA) and polyethylenemine (800 M w PEI) is prepared. A dopant solution to the growth solution, the dopant solution including an equal molar ration of sodium hydroxide (NaOH), glycolic acid (C 2 H 4 O 3 ) and antimony acetate (Sb(CH 3 COO) 3 ) in water is prepared. The dopant solution and the growth solution combine to generate a resulting solution that includes antimony to zinc in a ratio of between 0.2% molar to 2.0% molar, the resulting solution having a top surface. An ammonia solution is added to the resulting solution. A ZnO seed layer is applied to a substrate and the substrate is placed into the top surface of the resulting solution with the ZnO seed layer facing downwardly for a predetermined time until Sb-doped ZnO nanowires having a length of at least 5 μm have grown from the ZnO seed layer.
1. A method of growing p-type nanowires, comprising the steps of:
(a) preparing a nanowire growth solution of zinc nitrate (Zn(NO 3 ) 2 ), hexamethylenetetramine (HMTA) and polyethylenemine (800 M w PEI);
(b) preparing a dopant solution to the growth solution, the dopant solution including an equal molar ration of sodium hydroxide (NaOH), glycolic acid (C 2 H 4 O 3 ) and antimony acetate (Sb(CH 3 COO) 3 ) in water;
(c) mixing the dopant solution with the growth solution in a container to generate a resulting solution that includes antimony to zinc in a ratio of between 0.2% molar to 2.0% molar, the resulting solution having a top surface;
(d) adding an ammonia solution to the resulting solution;
(e) applying a ZnO seed layer to a substrate; and
(f) placing the substrate into the top surface of the resulting solution with the ZnO seed layer facing downwardly for a predetermined time until Sb-doped ZnO nanowires having a length of at least 5 μm have grown from the ZnO seed layer.
2. The method of claim 1 , wherein the predetermined time is about 24 hours.
3. The method of claim 1 , wherein the substrate comprises a material selected from a group consisting of: SiO 2 and a flexible polymer.
4. The method of claim 1 , further comprising the steps of:
(a) removing the substrate from the resulting solution;
(b) rinsing the Sb-doped ZnO nanowires in deionized water; and
(c) annealing the Sb-doped ZnO nanowires at a predetermined temperature.
5. The method of claim 4 , wherein the predetermined temperature is about 850° C.
6. The method of claim 1 , further comprising the step of applying a buoyant material to the substrate.
7. The method of claim 1 , wherein the zinc nitrate (Zn(NO 3 ) 2 ) is 25 mM in solution, the hexamethylenetetramine (HMTA) is 12.5 mM in solution, the polyethylenemine (800 M w PEI) is 5 mM in solution and the ammonium hydroxide is 0.8 M in solution.
8. The method of claim 1 , wherein the antimony acetate (Sb(CH 3 COO) 3 ) is added to the dopant solution in a 1:12 molar ratio.
9. The method of claim 1 , wherein the applying a ZnO seed layer step comprises the step of sputtering ZnO direct onto the substrate.
10. The method of claim 1 , wherein the substrate comprises a flexible material and wherein the applying a ZnO seed layer step comprises the steps of:
(a) applying an indium tin oxide (ITO) layer to the substrate; and
(b) sputtering ZnO onto the indium tin oxide (ITO) layer.
11. The method of claim 1 , further comprising the step of preheating the resulting solution to about 95° C. prior to the step of placing the substrate into the top surface of the resulting solution.