Optical studies of directly synthesized trans-polyacetylene films

Summary form only given. We study the electronic states, including the dipole forbidden ones, of a directly synthesized trans-polyacetylene film. 1 ) A main peak of reflection spectra of this film shifts to the lower energy side by more than 0.3 eV and becomes narrower than that of an ordinary thermoisomerized film, as seen in Fig. 1. This fact indicates that the conjugation length has long average length and narrow distribution width. Resonance Raman spectra also support this conclusion. We are in the process of studying luminescence excited near absorption edge and electro-reflectance by using such a film.