Optically detected magnetic resonance study of polaron and triplet-exciton dynamics in poly(3-hexylthiophene) and poly(3-dodecylthiophene) films and solutions

Abstract

The X-band optically detected magnetic resonance of poly(3-hexylthiophene) and poly(3-dodecylthiophene) films and solutions are described and discussed. The photoluminescence-enhancing features include (i) a strong, \ensuremath{\sim}15-G-wide, asymmetric peak at g\ensuremath{\simeq}2.003; (ii) a weak peak at g\ensuremath{\simeq}4.07; and (iii) a weak, \ensuremath{\sim}800-G-wide structure around g\ensuremath{\simeq}2. It is believed that feature (i) results from polaron recombination, and the others from the decay of two distinct intrinsic triplet polaronic excitons. The levels of all are apparently close to the band edges.