Photo-induced characteristic study of the smallest fullerene fragment, 1,6,7,10-tetramethylfluoranthene as an acceptor
Abstract
In the present study, a novel solution-processable 1,6,7,10-tetramethylfluoranthene (1), as the smallest fragment of fullerene, is synthesized and systematically studied for use as a non-fullerene acceptor in an organic solar cell (OSC). Molecule 1 has the potential to be synthesized on a large scale. Optical and electrochemical studies revealed that 1 has a high absorption range and an appropriate band gap, which is compatible with poly(3-hexylthiophene-2,5-diyl) (P3HT) as a donor. The morphology showed high intermixed blend with uniform distribution of donor–acceptor molecules. Steady state and time resolved photoluminescence studies showed efficient charge separation from the donor and acceptor. These studies can be confirmed by the conventional OSC device structure employing a blend of P3HT:1, which gives a power conversion efficiency (PCE) of up to 0.71% with an open circuit voltage (VOC) of 0.52 V and a fill factor (FF) of 44.89%. Despite this, the significant stability of the device, even after 60 h in open air, demonstrates that this molecule shows promising output and the result can be enhanced in the future with further optimization.