PHOTO-EXCITED AND DOPING-INDUCED ELECTRONIC STATES IN A POLY(PARA-PHENYLENE)-TYPE LADDER POLYMER

Incorporating a poly(p-phenylene) (PPP) backbone into a planar ladder polymer yields a molecular system with well-defined configuration and conformation. This chemical modification influences the electronic pro perties of PPP. We discuss the absorption spectra in the ultraviolet(U V) and visible range comparing the PPP-type ladder polymer (LPPP) to P PP and poly(p-phenylene vinylene) (PPV). The photoinduced absorption ( PIA) data are compared with the net change of the optical absorption u pon solution doping with FeCl3. The spectral dependence of the PIA in the near infrared region (NIR), as well as the behaviour with respect to time and pumplight-intensity are evaluated. These results show that the optical properties of the LPPP are much closer to PPV than PPP.