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Molecular engineering of high-performance non-fullerene acceptors (NFAs) is critical to enhance the power conversion efficiencies (PCEs) of bulk heterojunction organic solar cells (BHJ OSCs). In this work, density functional theory (DFT) and time-dependent DFT are employed to investigate the effects of π-bridge engineering on the photoelectric performance of high-performance NFA Y6. This π-bridge engineering principally involves (1) inserting different types of π-bridge units between the fused-ring core and the terminal unit of Y6, and then the π-bridge unit with better performance is screened for the next study, (2) inserting different numbers of screened π-bridge units between the fused-ring core and the terminal unit of Y6, and (3) modifying the side chains of the screened π-bridge unit with halogen atoms. Theoretical results predict that the selenophene π-bridge has superior properties in terms of dipole moment, exciton binding energy, and light absorption compared with other π-bridge units. In addition, studies on different numbers of selenophene π-bridges suggest that increasing the number of selenophene π-bridges has significant advantages in enhancing light absorption and electron transport capabilities for enhancing the short circuit current density (JSC). Meanwhile, the study of π-bridged side chains substituted with different halogen atoms indicates that the substitution of halogen atoms can play a significant role in reducing the exciton binding energy and raising the transferred charge amounts. The results obtained in this work are expected to be used to design new Y6 derivatives. [ABSTRACT FROM AUTHOR]

CaCu3Ti4O12 (CCTO) ceramics with desirable dielectric properties were prepared by a green gelcasting forming method combined with pressureless sintering. A non-toxic natural macromolecule, glutinous rice flour (GRF) was used as the gelling agent for the gelcasting process. The significant parameter, namely, the dosage of gelling agent was carefully studied so as to optimize the gelcasting process. The results showed that the dosage of GRF had evident effect on both gelcasting process and the final dielectric properties of CCTO ceramics. CCTO ceramics from the green body solidified with 3.5 wt% GRF showed relatively optimal dielectric properties, namely a dielectric constant up to 1.60 × 104 and a loss of only 0.063 (at 1 kHz test frequency). CCTO ceramics fabricated by this green gelcasting method have superior dielectric properties compared with that of the ceramics obtained by the dry pressing method. [ABSTRACT FROM AUTHOR]