The use of a synergistic additive NH₄SCN in constructing organic–inorganic hybrid perovskite films improves the quality of perovskite films, enhances the stability, and promotes the device efficiency.

As quasi two-dimensional semiconductors, bismuth oxychalcogenides (BOXs) have been demonstrated as potential candidates for high-speed and low-power electronics because of their exceptional environmental stability and high carrier mobility. Here, thermodynamics of growth and a series of intrinsic defects in BOXs are studied using first-principles calculations. Comparing the chemical potential phase diagrams of BOXs, we find that it is easier to grow Bi₂O₂Se than to grow Bi₂O₂S or Bi₂O₂Te. It is most difficult to grow stable Bi₂O₂Te because of the existence of various binary phases. Under Se-poor conditions, the intrinsic point defects of Bi replacing Se (Bi_Se) and Se vacancy (V_Se) can form easily and behave as donors because of low formation energy, which is the reason for the n-type character of as-grown Bi₂O₂Se in experiments. For Bi₂O₂S, the donor point defect of Bi substituting S (Bi_S) is also dominant, leading to an n-type carrier. This study of thermodynamics and the physics of intrinsic point defects provides a valuable understanding of BOXs.

We prepared a graphene/ionic liquid (G/IL) composite material by the hybridization of G and an IL for use as a lubricating oil additive. The friction coefficient and wear volume of a base oil containing 0.04 wt% of the G/IL composite was reduced by 45% and 90%, respectively. Furthermore, the base oil containing the G/IL composite exhibited better lubricating properties than the base oil containing G, IL, or a mixture of IL and G at the same mass fraction. A synergistic lubrication mechanism was also revealed. The G/IL composite was adsorbed and deposited on the wear surface, forming a more ordered protective film and a unique tribochemical reaction film during rubbing. Therefore, the G/IL composite exhibited the synergistic lubricating effects of G and IL, which significantly improved the lubricating performance of the base oil. This study also suggested a way to limit the out-of-plane puckering of G at the macroscale.