Doping level and work function control in oxidative chemical vapor deposited poly (3,4-ethylenedioxythiophene)

Abstract

Control over doping level and work function is achieved for poly(3,4-ethylenedioxythiophene) (PEDOT) films deposited by oxidative chemical vapor deposition (oCVD). Surface analysis reveals the equivalence of the surface and bulk compositions for the oCVD films. The oCVD PEDOT polymer chains doped solely with Cl- ions. By increasing the substrate temperature used for deposition, the doping level was monotonically increased from 17 to 33 at. %, resulting in a corresponding ability to tune the work function from 5.1 to 5.4 eV. The controllability of doping level and work function of oCVD PEDOT offers great potential advantages for organic devices. (c) 2007 American Institute of Physics.