I am working with PEDOT:PSS thin films that I routinely produce by spin coating on play microscope slides. For various measurements I would need to have films of different thicknesses.
Electropolymerisation is not an option and I can not go much lower in spinning speed to increase film thickness in that way.
So I was wondering if it would make sense to spin coat several layers of PEDOT:PSS on top of each other?
I have not seen people doing it so I am afraid there is an obvious reason not to do this that I am not aware of.
Thank you!
kind regards,
Karen
Dear Karen,
Yes, you can increase the thickness of film with sequential spin coating. But the thickness of the deposited film won't be uniform over the entire area of the substrate.
Good luck.
Dear Khan,
thank you very much for your answer.
what is the main reason for non-uniformity? the roughness of the PEDOT film compared to glass substrate?
would you assume that if measurements are preformed in the middle of the sequentially spin coated films they can be compared across different surfaces?
kind regards,
Karen
Dear Karen
Greetings
There many factors affect on the homogeneity and uniformity or roughness of the prepared film as a result using spin coating deposited on glass substrate, if you want to prepare thick or thin films:the factors affected are : the temp. of the liquid polymerization, the velocity of the spin coating, the concentration of the liquid, the time of rotation.Many layers.you can deposited on substrate using low concentration of solution at room temp. or you can deposited one layer by using high concentration at low velocity rotation.
With best regards
Dear Karen,
I think the main reason in your case wont be the roughness. Let me explain you, what kind of problem you would face in the sequential spin coating of the PEDOT:PSS: Suppose you deposit the first layer of the PEDOT:PSS , and then you put a droplet of the PEDOT:PSS for second deposition, the droplet will react with first deposited layer and so you will have terrible film. The middle of the film would suffer more :)
Good luck.
Hej!
Thank you very much for your answers.
@ Khan: how do you mean PEDOT will "react" with the already coated layer?
I have however tried to spin coat PEDOT:PSS on Orgacon (=commercial PEDOT:PSS printed on PET) without bigger problems.... but lets see how it goes.
Thank you!
kind regards,
Karen
Hej Ghazale!
I spin in 2 steps - 45s at 500rpm and 1min at 1500rpm : )
thanks!
best regards
Dear Karen, did you get progress in your multiple spinning of PEDOT:PSS? this is an interesting task. In my experience, the second spinning yield a lower thickness films, after that no improvement in the thickness is achievable. Waiting for news from you. Thanks. Joseph.
Hej Joseph!
we have managed to successfully spin coat the second layer and the film was visually thicker (so less transparent); however I have admittedly not measured the thickness, neither the surface roughness. no visual inhomogeneities were present though.
best,
Karen
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Thin Films and Nanotechnology