Photoluminescence and optically detected magnetic resonance in polythiophene and poly(3-alkylthiophenes); substitution, disorder and ageing effects

Abstract The influence of side-group substitution, disorder, and ageing in the photoluminescence (PL) and related optically detected magnetic resonance (ODMR) has been studied. Alkyl substitution causes energy shifts and broadening in the PL spectra. Ageing and disorder has a profound effect on the PL and PL excitation spectra, and a possible effect on the temperature dependence of the ODMR intensity. Our results suggest that ageing substantially increases the subgap absorption tail and this in turn displaces the PL spectrum to lower energies due to reabsorption.