RESONANCE RAMAN-SCATTERING FOR MID-GAP ABSORPTION-BANDS IN HALOGEN-DOPED MX CHAINS

Resonance Raman spectra for the mid-gap absorption bands were measured in chlorine-doped quasi-one dimensional [Pt(en)(2)][Pt(en)(2)Cl-2](Cl O4)(4) (en=ethylenediamine) single crystals, in order to classify the origin of the Raman modes relevant to the photo-induced defect states. We found that the intensity of the Raman modes located between 270 an d 285 cm(-1) relative to that of the Raman modes between 285 and 295 c m(-1) increases with increasing the chlorine doping time. This fact st rongly suggests that the origin of the former Raman modes is attribute d to the hole polarons and that of the latter ones is assigned to the electron polarons.