Infrared and Optical Absorption in Poly(4,4′diphenylenediphenylvinylene)

Abstract

We have recently published results on the optical absorption and luminescence of poly(4,4′-diphenylenediphenylvinylene) [PDPV] which provide evidence for the formation of polaron and bipolaron defects during doping with AsF₅ [1]. Here we present results on the infrared absorption. Doping with AsF₅ results in the appearance of defect bands at 900 cm⁻¹, 1560 cm⁻¹ and a broad structured absorption with peaks at 1185 cm⁻¹, 1240 cm and 1300 cm⁻¹. We have also observed an absorption at ~ 0.42 eV which is consistent with an electronic transition from the valence band to lower polaron level for a singly-charged defect. All these features are removed on compensation,indicating their origin in the charge-transfer reaction that occurs during doping.