A two-dimensional Raman spectroscopic study on the structural changes of a polythiophene film during the cooling process

摘要

Raman spectra of a polythiophene fim measured over a temperature range 298-98 K were analyzed using generalized two-dimensional correlation spectroscopy.In the 1600-1250 cm~(-1) region,the asynchronicity of the bands indicates the existence of different speciesin the investigated polythiophene sample.At least four distinct bands at 1485,1454,1418,and 1360 cm~(-1) were identified.Among them,the band at 1454 cm~(-1),attributed to the neutral species of PTh,is found to be sensitive to the temperature-induced structural changes of the polythiophene film,while the bands of the oxidized species are less sensitive to the temperature change during the cooling process.