The mitigation of interfacial charge accumulation in solution-processed organic light-emitting diodes (s-OLEDs) is an effective method to improve device performance. In this study, the polar solvent vapor annealing (PSVA) method was used to treat two layers in s-OLED, PEDOT:PSS and mCP:DMAC-DPS emitting layers, separately, to optimize the carrier transmission and balance. After the double-layer PSVA treatment, the current efficiency increased, the lifetime of the device is improved, the efficiency roll-off alleviated from 33.3% to 26.6%, and the maximum brightness increased by 31.3%. It is worth mentioning that the work function of the EML interface reduced by 0.36 eV, and the initial injection voltage of the electrons also reduced. Simulating the solubility of the LUMO and HOMO molecule parts of the mCP and DMAC-DPS, it was found that the LUMO parts had stronger polarity and higher solubility in polar solution than the HOMO parts. By comparing the untreated luminescent layer films, it was found that the PSVA treatment improved the uniformity of the film morphology. We may infer that a more ordered molecular arrangement enhances carrier transport as the LUMO parts tend to be close to the surface and the reduced local state traps on the EML surface promote electron injection. According to the experimental results, the injection of holes and electrons is enhanced from both sides of the EML, respectively, and the charge accumulated at the interface of s-OLEDs is significantly reduced due to the improvement of carrier-transported characteristics.

A 3D icing simulation code is developed in the open-source CFD toolbox OpenFOAM. A hybrid Cartesian/body-fitted meshing method is used to generate high-quality meshes around complex ice shapes. Steady-state 3D Reynolds-averaged Navier-Stokes (RANS) equations are solved to provide the ensemble-averaged flow around the airfoil. Considering the multi-scale nature of droplet size distribution, and more importantly, to represent the less uniform nature of the Super-cooled Large Droplets (SLD), two droplet tracking methods are realized: the Eulerian method is used to track the small-size droplets (below 50 μm) for the sake of efficiency; the Lagrangian method with random sampling is used to track the large droplets (above 50 μm); the heat transfer of the surface overflow is solved on a virtual surface mesh; the ice accumulation is estimated via the Myers model; finally, the final ice shape is predicted by time marching. Limited by the availability of experimental data, validations are performed on 3D simulations of 2D geometries using the Eulerian and Lagrangian methods, respectively. The code proves to be feasible and accurate enough in predicting ice shapes. Finally, an icing simulation result of the M6 wing is presented to illustrate the full 3D capability.

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White organic light‐emitting diodes (WOLEDs) have attracted extensive attention and are considered as an ideal next‐generation lighting source. However, maintaining high efficiency and high color rendering index (CRI) in WOLEDs still faces great challenges. The charges accumulation at the interface leads to nonradiative recombination and further Joule heat, which is a source of efficiency decrease and device degradation. In this paper, the interfacial exciplex is designed as the host for high efficiency; the blue thermally activated delayed fluorescence (TADF) material and the red phosphorescent material are employed as guests for high CRI. Due to the interfacial exciplex host, electrons don't need to overcome the potential barrier to inject into the light‐emitting layer, but can directly compound with holes at the interface, so as to release the interfacial accumulated charges and improve the recombination efficiency of carriers. Also, a suitable energy level gradient for hole injection transmission is constructed. Finally, WOLEDs with a current efficiency of 52.8 cd A−1, an external quantum efficiency of 22.9 %, the Commission Internationale de I'Eclairage (CIE) coordinate of (0.35,0.39), and the high CRI of 80 are obtained, which are the highest values ever achieved by the solution processed WOLEDs based on blue TADF emitters.

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