Through the combination of transient spectroscopy and theoretical simulations, an accelerated singlet fission (SF) process was evidently observed in the strongly coupled H-type-like aggregation thin films of a dipyrrolonaphthyridinedione skeleton. Results elucidate that in this H-type-like aggregation, the substantially stabilized charge transfer (CT) state is close in energy with singlet and excimer states, resulting in a CT/excimer mixed state, which could drive excited-state population escaping from excimer trap and promote an ultrafast and highly efficient SF process. Our results not only enrich the limited capacity of SF materials but also contribute to an in-depth understanding of SF dynamics in H-type aggregation, which is of fundamental importance for designing new SF sensitizers and implementing practical SF applications.

The microscopic mechanism of high color purity was elucidated by computational investigation.

For the great progress in panel display devices, it is necessary to have a thorough understanding of white organic light-emitting diodes (WOLEDs). In this work, we confirmed a reasonable mechanism of the white light emission with dual emission peaks in the studied compound; the mechanism is that the white emission could be formed with the 0−0 peak and the low-energy emission peak, where the latter is constituted by the highfrequency normal modes with larger Huang−Rhys factors. Moreover, in order to systematically understand the work performance in different surrounding environments, the emission spectra in solution, crystal phase, and amorphous phase were simulated. In view of the fact that the maximum emission wavelength of this complex corresponds to the 0−0 peak, the red-shifted emission from the solution to the crystal phase in experiment could be attributed to the smaller energy gap of the d−π* transition and the lower reorganization energy of the ground state (λ gs ) in the crystal phase. Additionally, our calculations indicate that the smaller energy gap of the π−π* transition and the smaller λ gs in the amorphous phase would cause the red-shifted emission from the crystal phase to the amorphous phase, where the smaller energy gap plays the primary role. In the meantime, it is found that vibronic couplings play a predominant role in photoluminescence efficiency changes caused by environmental effects. Our computational study will provide valuable information to the rational design of optical applications with white emission, which is meaningful to the future development of WOLEDs.

With the advancement of technology and advances in technology, the research on drones has become more and more in-depth, and the practical application fields have become more extensive. Its unparalleled advantages also play an important role. At present, drone technology has also gradually Mature. Drones are creating a new agricultural revolution. It is estimated that the size of drones in the agricultural market will reach billions of dollars in the next few years. As editor of the UN Food and Agriculture Organization and the International Telecommunication Union’s research report on “UAVs and agriculture”, information expert Gerard Sylvester said that as farmers work to adapt to climate change and meet other challenges, drones are expected to help the entire Agricultural enterprises improve efficiency.