Photophysics and morphology investigation based on perylenetetracarboxylate/polymer photovoltaic devices

A novel perylenetetracarboxylate, tetrabenzyl perylene-3,4,9,10-tetracarboxylate (TBEP), was synthesized and acted as an acceptor used in polymer photovoltaic devices. TBEP is expected to have high exciton diffusion range and high charge mobility. Photovoltaic devices of indium-tin-oxide (ITO)/PEDOT-PSS/MEH-p-phenylene vinylene (PPV)+TBEP/Ba/Al were fabricated and their photovoltaic parameters were measured. Photophysics of the blend material and influence of annealing on performance and morphology of these devices were discussed. Annealing process resulted in the formation of TBEP crystal network, which increases the external quantum efficiency (EQE) and energy conversion efficiency (ηe) of the photovoltaic devices by a factor of five compared with non-annealing ones.