I synthesized metal oxides with different morphology by chemical route, now i have it in powder form. I want to make thin film of this material o glass substrate to measure gas sensing properties. I went through literature but i am confused for spin coating process.
Please suggest me how can i get uniform and good adhesive film by spin coating (100-500 nm thick).
Which solvent is good for metal oxides CuO, NiO, ZnO etc?
What about the quantity of solvent and material (molarity)?
How much viscosity?
What about Speed RPM and time?
I have to follow only single step or multi step spin process(first slow then faster)?
I have to heat it after every spin to evaporate solvent?
Please suggest about spin coating, it will be helpful.
Q 1. Please suggest me how can i get uniform and good adhesive film by spin coating (100-500 nm thick).
A 1. The uniformity of the film and adhesion of the material on the glass substrate depends on the viscosity of the solution and RPM.
Q 2. Which solvent is good for metal oxides CuO, NiO, ZnO etc?
A 2. Each material has its unique properties and hence the best solvent. For ZnO, the best solvent is Dimethyl Sulfoxide (DMSO).
Q 3. What about the quantity of solvent and material (molarity)?
A 3. Molarity can be better decided experimentally. It will be better if you prepare different solutions of various molarities and then investigate using various characterization techniques.
Q 4. How much viscosity?
A 4. the solution should be enough viscous. If it is less viscous, almost whole amount of it will be removed out while spinning.
Q 5. What about Speed RPM and time?
A 5. In general, people prefer to operate spin coater at 3000 rpm for 60 sec to get uniform thin film.
Q 6. I have to follow only single step or multi step spin process(first slow then faster)?
A 6. For thin film, single step is sufficient.
Q 7. I have to heat it after every spin to evaporate solvent?
A 7. For multi-layer deposition, evaporation of the solvent at each step is necessary.
For further details, you may read the article:
Article Fabrication of nanostructured yttria stabilized zirconia mul...
Hi Chandra !
For highly crystalline metal oxide, you can make viscous paste to spin coat using mixed solvents in the following combinations
1)ethyl cellulose and alpha-terpineol
or
2)absolute ethanol and triton X
or
3)ethanol and nitric acid
For more info go through the document attached herein.
Q 1. Please suggest me how can i get uniform and good adhesive film by spin coating (100-500 nm thick).
A 1. The uniformity of the film and adhesion of the material on the glass substrate depends on the viscosity of the solution and RPM.
Q 2. Which solvent is good for metal oxides CuO, NiO, ZnO etc?
A 2. Each material has its unique properties and hence the best solvent. For ZnO, the best solvent is Dimethyl Sulfoxide (DMSO).
Q 3. What about the quantity of solvent and material (molarity)?
A 3. Molarity can be better decided experimentally. It will be better if you prepare different solutions of various molarities and then investigate using various characterization techniques.
Q 4. How much viscosity?
A 4. the solution should be enough viscous. If it is less viscous, almost whole amount of it will be removed out while spinning.
Q 5. What about Speed RPM and time?
A 5. In general, people prefer to operate spin coater at 3000 rpm for 60 sec to get uniform thin film.
Q 6. I have to follow only single step or multi step spin process(first slow then faster)?
A 6. For thin film, single step is sufficient.
Q 7. I have to heat it after every spin to evaporate solvent?
A 7. For multi-layer deposition, evaporation of the solvent at each step is necessary.
For further details, you may read the article:
Article Fabrication of nanostructured yttria stabilized zirconia mul...
Hello Mr. Goyal,
Your concern is to the synthesis of thin films on a glass substrate and you have already synthesized metal oxides powder (i think, it's not clear in your question).
If you want to the synthesized thin film of nanoscale order of any material you have to follow sol-gel spin coating process in which you chose source materials (salts) and solvents, In case of ZnO, you have to use ZnAc and dissolve in ethanol (2-Methoxy) and also add stabilizer.
So I think, nanoscale thin film from ZnO powder is not possible with chemical techniques and for your purpose for gas sensing, if its resistance based too difficult due to uniform distribution.
If you want to synthesize thin film form synthesized powder you can you physical techniques like RF-sputtering (In ZnO).
Thanks
Taking ZnO as an example, as I work in the field of organic solar cells, you may find quite a variety but similar ways of preparing films in the literature. However, here I give you some details using the sol gel method. You need the following (all of which you can get from Sigma Aldrich or any other chemical company):
· ZnAcetate (Zn(CH3CO2)2), Sigma-Aldrich, 99.99% trace metals basis, 383317
· 2-methoxyethanol anhydrous (CH3OCH2CH2OH), Sigma-Aldrich, 99.8%, 284467-
· Ethanolamine (NH2CH2CH2OH), Sigma-Aldrich, purified by redistillation, ≥99.5%, 411000
Now Weigh 275 mg of Zinc Acetate in a bottle with the stirring bar, Add 2.5 ml of 2-methoxyethanol, then finally Add 78 μl of ethanolamine. Keep under vigorous stirring for minimum 3h (to 12h). Then spin-coating under ambient atmosphere with 5000rpm, time : 30 sec, acc : 1000 rpm.s-1. Finally annealed the substrate at 170 °C for at least 30 mins.
You may also prepare ZnO nanoparticles and later dessolve in ethanol/butanol or any other reasonable solvent before spin coating using other methods found in the literature.
I hope this helps.
Thanks for your kind suggestions.
But i already synthesized ZnO Nano structure by hydrothermal method. Now i want to coat thin ZnO Powder on glass substrate by spin coating.
Please suggest.
Then you should consider the last paragraph of my last submission using butanol. And spin coating at 3000 rpm, 4000 rpm and 5000 rpm and try annealing at 120-130-140 °C
Hello, Just follow any paper where mention your process. You can get plenty of papers for ZnO nanoparticles are derived by spin coating process ,which initially followed by sol-gel precursor solution.
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