The development of new strategies to construct on-demand porous lattice frameworks from simple motifs is desirable. However, mitigating complexity while combing multiplicity and reversibility in the porous architectures is a challenging task. Herein, based on the synergy of dynamic intermolecular interactions and flexible molecular conformation of a simple cyano-modified tetraphenylethylene tecton, eleven kinetic-stable hydrogen-bonded organic frameworks (HOFs) with various shapes and two thermo-stable non-porous structures with rare perpendicular conformation are obtained. Multimode reversible structural transformations along with visible fluorescence output between porous and non-porous or between different porous forms is realized under different external stimuli. Furthermore, the collaborative of flexible framework and soft long-chain guests facilitate the relaxation from intrinsic blue emission to yellow emission in the excited state, which represents a strategy for generating white-light emission. The dynamic intermolecular interactions, facilitated by flexible molecular conformation and soft guests, diversifies the strategies of construction of versatile smart molecular frameworks.

Effective optical constants of Ag thin films are precisely determined with effective thickness simultaneously by using an ellipsometry iterated with transmittance method. Unlike the bulk optical constants in Palik's database the effective optical constants of ultrathin Ag films are found to strongly depend on the thickness. According to the optical data two branches of thickness dispersion of surface plasmon energy are derived and agreed with theoretical predication. The thickness dispersion of bulk plasmon is also observed. The influence of substrate on surface plasmon is verified for the first time by using ellipsometry. The thickness dependent effective energy loss function is thus obtained based on this optical method for Ag ultrathin films. This method is also applicable to other ultrathin films and can be used to establish an effective optical database for ultrathin films.

The perovskite/Cu(InGa)Se₂ (PSC/CIGS) tandem configuration is an attractive way to achieve an ultra-high efficiency and cost-effective all-thin-film solar cell. However, the imbalanced efficiencies of the constituent sub-cells and the bandgap mismatch generally limit the achieved overall power conversion efficiency (PCE). Herein, by combining Cl bulk incorporation and piperazinium iodide (PDI) surface treatment for the CsFAPb(IBr)₃ system, we have successfully reduced the bulk and interface defect densities and greatly enhanced the open-circuit voltage and thus the PCE of the 1.67 eV-bandgap PSCs. The accompanied high activation energy of ion migration has also led to high photostability with suppressed phase segregation. By integrating a highly efficient and highly infrared transparent 1.67 eV PSC top cell with various bandgap CIGS solar cells of comparable efficiency, we have demonstrated that a 1.04 eV CIGS bottom cell achieved ideal bandgap matching and realized a four-terminal tandem cell with a calculated tandem efficiency of 28.4%, currently the highest for PSC/CIGS tandem cells. The PSC device showed no degradation after 600 h of operation at 50 °C and was attenuated by only ∼10% at 1300 h. Moreover, the achieved well-matched J_sc between top and bottom sub-cells and the adopted inverted-PSC configuration have paved the way for producing highly efficient monolithic two-terminal PSC/CIGS tandem devices in the near future.