polythiophene based polymers of Poly (3-hexylthiophene-2, 5-diyl) with regio-regular
structure to elucidate the intra-and inter-chain hopping mechanisms. The LF dependent
muon-spin depolarization rate indicates the occurrence of dimensional crossover from 1
dimensional intra-chain spin diffusion to 3 dimensional inter-chain spin diffusion at 25 K.