H-aggregation of the amphiphilic dye TDPI: Photophysical, electrochemical, DFT and SAXS studies

A 1,8-naphthalimide based small molecular acceptor for polymer solar cells with high open circuit voltage

“…The formation of H-aggregates by NI molecules may be beneficial for electron transport upon formation of a blend film with the donor polymers. 20 The enhanced absorption coefficient of NI-T-NI above 450 nm also demonstrated the occurrence of a stronger p-p stacking in the solid state. 26 The optical band gap (E g,opt ) of NI-T-NI estimated by the absorption edge of 488 nm in the film absorption spectrum is 2.54 eV.…”

“…Because crystalline NI-T-NI aggregates exhibit a higher electron scattering density than amorphous PCDTBT-C12 aggregates,26 the black domains were formed, as shown in Fig.7b, after thermal annealing could be ascribed to the H-aggregates of NI-T-NI molecules. The formation of more Haggregates by NI-T-NI molecules after thermal annealing is beneficial for the electron transport in the active layer 20. ConclusionsIn conclusion, we have used DCHA to synthesize a new small molecular acceptor NI-T-NI, which is composed of a central thiophene core and two 1,8-naphthalimide terminal groups.…”

“…18,19 Although NI based small molecules were rarely used as acceptor materials for organic/ polymer solar cells, a PCE of 5.3% has been achieved for the NI based small molecular acceptor that contains two strong electron withdrawing cyano groups. 20 In this work, we have developed a new small molecular electron acceptor NI-T-NI, which is composed of two terminal NI moieties and a central thiophene bridge. Direct C-H activation (DCHA) has been used to synthesize NI-T-NI.…”