Investigation of Structure of PEDOT: PSS Thin Films Using X-Ray Reflectivity.

Thin Films of PEDOT: PSS on the Indium Tin Oxide substrate were prepared at different spinning speed, for instance, 1000 rpm, 1500 rpm, 2000 rpm & 4000 rpm by spin-coating technique. The out-of-plane structure of the thin films was determined by x-ray reflectivity technique to produce electron density profiles, thickness and roughness. High spinning speed (2000 and above) causes segregation of PSS at the top. The overall reduction in electron density of the films indicates that the high electron density component of the film is removed from top along the fluid due to strong centrifugal force at the top. The results bring interesting insight into the structure of PEDOT: PSS films which is likely to influence its current transport properties. [ABSTRACT FROM AUTHOR]