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Crystalline sponge method represents a rather new trend in structural analysis. This method is to use networked porous metal complexes as “crystalline sponges”, which does not require the crystallization of the sample. It has large and regular cavities which can absorb the target molecules like sponges and arrange them in an orderly manner, so that their structures can be determined with X-ray diffraction. In this review, we focus on recent trends in crystalline sponge method. Following an introduction in the field, a first main section covers the birth of crystalline sponge method and the improvement of crystal synthesis method. The further section covers structural confirmation, including the guest molecular structure determination and host-guest interactions. The next main section covers the expansion of crystalline sponge method, such as the applications in synthesis, other crystalline sponge and visual observation. The final section covers the limitations and prospects of the crystalline sponge method. [ABSTRACT FROM AUTHOR]

For solution-based small-molecule organic photovoltaic cells (SM BHJ), thermal annealing is often regarded as a very vital processing to yield high-efficiency devices. Here, the device with the photoactive p-DTS(FBTTh2)2:PC60BM blends has been studied by varying the annealing temperature. The highest power conversion efficiency (PCE), fill factor (FF), and short-circuit current ( Jsc) has been achieved after the device was annealed at the temperature of 80 °C. X-ray diffraction (XRD) displayed that the p-DTS(FBTTh2)2 tends to form big islands with well-defined crystalline structure (long coherence length) surrounded by small islands of the PC60BM after annealing, and reached the largest grain size of 27 nm after annealing at 80 °C. AFM images demonstrated the most sufficient phase separation within the photoactive blend layer after annealing at 80 °C, which provides good photogenerated excitons dissociation. Such improvements have proved beneficial to decrease the ohmic loss and recombination in carrier-transport process via measuring series resistance and shunt resistance as well as hole mobility. This work opens up a new way to understand the relationship between thermal annealing and molecular interaction from the viewpoint of lattice relaxation. [ABSTRACT FROM AUTHOR]