muSR study of charge carrier dynamics in active layer of hybrid solar cells

Recently, hybrid solar cell has been developed owing to the combined advantage between organic material P3HT and inorganic material ZnO. We have studied the microscopic intrinsic charge carrier dynamics in active material of P3HT:ZnO and P3HT:ZnO:PCBM along and perpendicular to the chain by using LF muSR. We found that the charge carrier mobility changes from intra-chain to inter-chain diffusion both above 25 K. We have also measured charge carrier dynamics of P3HT:ZnO with light irradiation. We found small changes of asymmetry when light irradiation on and off, however we cannot observe significant effect due to low intensity of light irradiation. Here, we propose to study the effect of high intensity light irradiation to elucidate the intra- and inter-chain charge carrier dynamics in P3HT:ZnO and P3HT:ZnO:PCBM by using LF muSR at various temperature down to 10 K from 0 to 3950 G.