Designing an asymmetrical isomer to promote the LUMO energy level and molecular packing of a non-fullerene acceptor for polymer solar cells with 12.6% efficiency

PSCs based on PBDB-T:MeIC1 achieved a larger Voc and Jsc and thus boosted the PCE compared to PBDB-T:MeIC-based PSCs.

A 9,9′-spirobi[9H-fluorene]-cored perylenediimide derivative and its application in organic solar cells as a non-fullerene acceptor

A structurally orthogonal molecule (SBF-PDI4) with a 9,9′-spirobi[9H-fluorene] (SBF) core and four perylenediimide (PDI) at periphery was developed for use in polymer solar cells. Proper LUMO energy level (−4.1 eV) and good light absorption ability over 450–550 nm make it an excellent non-fullerene acceptor.

A polymer acceptor with an optimal LUMO energy level for all-polymer solar cells

A new polymer acceptor based on the BNBP unit with an optimal LUMO energy level has been developed. The resulting all-polymer solar cells show high PCEs, remarkably highVocvalues and small photon energy losses.

A comparative study of the effect of fluorine substitution on the photovoltaic performance of benzothiadiazole-based copolymers

Fluorination on the acceptor unit is effective to lower both the HOMO and LUMO energy level of the copolymer.

Study on the photophysical and electrochemical property and molecular simulation of broadly absorbing and emitting perylene diimide derivatives with large D–π–A structure

A simple synthetic route to obtain perylene diimide candidate materials with large conjugation, obvious ICT, broad light-absorption/emission, concentration-dependant ð–ð staking induced fluorescence and low-lying LUMO energy level.

Reaction of cobalt porphycene with hydride reagents: spectroscopic detection of Co–H porphycene species and formation of Co–SnR3 porphycene species

The reaction of tetrapropylporphycenatocobalt(III) with tributyltin hydride generates a cobalt(III)–hydride porphycene detectable by UV-vis spectroscopy under diluted conditions, whereas it is impossible to characterize hydride species of cobalt porphyrins. One of the reasons for the stability of the porphycene hydride species is that the porphycene ring has a lower LUMO energy level due to the decrease in the symmetry of the ligand character. However, the hydride species in a highly concentrated solution of the complex is easily converted into the cobalt(II) species via dimerization or reaction of the hydride with excess tributyltin hydride through hemolysis of the Sn–H/Co–H bonds. When the Co(III) porphycene is reacted with LiBHEt3 , the final product is the cobalt(III)–ethyl complex formed by β-rearrangement during the reaction of the hydride species and diethylborane in a solvent cage. In the reaction of tetrakistrifluoromethylporphycenatocobalt(III) with tributyltin hydride, the dominant reaction pathway includes one-electron reduction of the porphycene ring together with radical coupling of the tin reagent rather than the net hydride transfer. This finding suggests that the delicate control of the LUMO energy level influences the stability of the hydride species. The tetrapropylporphycenatocobalt(III) complex with tributyltin or triphenyltin hydride in the presence of AIBN produces the corresponding Co(III)– trialkyltin complex. This complex was characterized by 1H NMR spectroscopy.