Surface, interface and electronic studies on anthracene derived polymeric thin films for OLED applications

Abstract

We have investigated semiconducting aromatic aliphatic polyethers based on either distyrylanthracene (Polymer A) or distyrylanthracene, distyrylbenzothiadiazole and distyrylcarbazole (Terpolymer B) chromophores separated by aliphatic undecane spacers that were deposited as thin films onto PEDOT:PSS by X-ray Photoelectron spectroscopy (XPS), depth-profiling XPS, and Reflection Electron Energy Loss Spectroscopy (REELS) techniques. XPS measurements demonstrated the quality of the prepared films. They also showed that for the Terpolymer B sample there is an excess of PSS dopant in the film surface, which was further corroborated through argon ion sputtering process coupled to the XPS acquisition. N1s XPS results suggest that sulphonic groups present in the PSS molecule might interfere in the Terpolymer B backbone by protonating their nitrogen atoms. From REELS data, π − plasmon peaks were derived for Polymer A and Terpolymer B thin films. In addition, Spectroscopic Ellipsometry and Photoluminescence Spectroscopy were applied for the evaluation and the determination of the optical properties as well as the thickness of the photoactive polymeric films and the emission characteristics, respectively. Semiconducting aromatic-aliphatic polyethers based on anthracene were studied by spectroscopic techniques. Spectroscopic Ellipsometry and Photoluminescence Spectroscopy were applied for the evaluation and the determination of the optical properties. Information on film's electronic, interface and optical properties and electronic transitions were obtained.