Low energy neutral and charged excitations in α-sexithienyl: a polythiophene model compound

Photoluminescence and photoconductivity action spectra of α-sexithienyl (T6) are reported and discussed. The photoluminescence spectrum of oriented sublimed thin film of T6 at 4.2 K shows a one to one correspondence with similar spectra of good crystalline quality of chemically synthesized polythiophene (PT). The photoconductivity action spectrum of T6 is complementary to the luminescence excitation spectrum indicating that the electron-hole pair creation is the dominant channel of non radiative decay for excitation higher than the bottom of the lowest Bu excitonic band. We suggest T6 as a good model compound for PT