Dear All,
I am interested in spin coating polymer film over a glass substrate. I have tried the following cleaning procedure:
1) Washing in soap solution
2) Sonication in acetone, IPA and DI water each for 10 minutes
3) Drying at 200oC
But when I try to spin coat the sample (PEDOT:PSS) it is flying away leaving some patches around. I have tried with different RPM also, but that was not helpful. Please give me some suggestions..
Thanking you all in advance
Plasma treatment is best.
you can make your own plasma system. Take a glass bottle / jar. evacuate it to some smaller pressure. Then place it in microwave oven. There will be air plasma. Try to introduce oxygen if possible in the glass bottle after evacuation. Even otherwise also it is ok.
This would make your glass slides hydrophillic. Other gasses you may have to use if you want to make it hydrophobic (Flourine - bit difficult to handle).
When you clean your substrate with acetone and then with IPA, don't go any further! It's actually the water that you use at the end that spoils your substrate again with coffe stains formed with the high temperature. This stains are the reason of PEDOT patches.
IPA is used because it removes the stains of acetone and then dries very fast; so you don't have to use high temperature to remove it. At best, just incline your sample on one corner in order to let the film to form a drop, that you can easly remove by a small shake. And that's it.
You can even use a gentle air flow, if you see the glass still wet, but normally the IPA dries in few seconds.
If you want to further increase you hydrophilicity and you don't have a plasma treatment, you can go with a simple UV lamp treatment, leaving the sustrate, after the cleaning with acetone/IPA, 5 to 10 minutes under a UV lamp.
Thank you Dear Claudio and Nabhiraj Sir.....
Can you please tell me whether any prior substrate treatment is needed before washing it with acetone and IPA ?
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