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The mechanisms governing electric field and partial discharge (PD) under stress cone dislocation remain unclear. This study employs the finite element method to explore the relationship between the electric field, externally applied voltage, and length of dislocation. Subsequently, the correlation between voltage and electric field is determined. The relationship between voltage and PD is established through PD tests conducted under stress cone dislocation conditions. By considering the influence of voltage, the association between the electric field and PD is established, revealing the mechanism of PD initiation by electric field distortion in joints. The findings suggest that the lifetime and reliability were increased by wrapping semi‐conductive self‐adhesive tape around the exposed cross‐linked polyethylene (XLPE) insulation layer. The electric field at a specific location is approximately proportional to the applied voltage. However, the slope is influenced by the composite insulation interface and the radial distance of the copper conductor. When crossing the interface between the XLPE insulation layer and the accessory insulation layer, the slope decreases significantly. The threshold for electric field PD is determined by examining the electric field distribution and the PD inception voltage during testing. When the voltage is sufficiently high, significant electric field distortions can occur at multiple points in the joint, potentially leading to concurrent PDs at several locations. [ABSTRACT FROM AUTHOR]

Although sensitizing traditional fluorescent dyes with thermally activated delayed fluorescence (TADF) exciplexes has been extensively studied, the device performance of solution‐processed organic light‐emitting diodes (OLEDs) still lags far behind in this regard. Herein, the novel exciplex with high up‐conversion efficiency composed of a triazatruxene‐based donor and a triazine‐based acceptor is employed as a TADF sensitizer to fluorescent dye in solution‐processed hyperfluorescent OLEDs. Benefiting from the small activation energy for triplet up‐conversion and less non‐radiative recombination of triplet excitons, the new TADF exciplex can up‐convert efficiently non‐radiative triplet excitons through reverse intersystem crossing. Besides, expeditious up‐conversion processes also shorten the residence time of triplet excitons, giving rise to significant suppression of detrimental Dexter energy transfer from the exciplex sensitizer to the dopant. By maximizing the triplet up‐conversion efficiency of exciplex sensitizers, the optimized OLEDs achieve a maximum external quantum efficiency (EQEmax) of 16.0%, which is the first report for the solution‐processed exciplex‐sensitized hyperfluorescent OLEDs with EQEmax exceeding 15%. These results validate that the up‐conversion efficiency of triplet excitons in the exciplexes strongly affects the performance of exciplex‐sensitized fluorescent devices, and the triazatruxene‐based molecules are promising donor candidates for constructing the exciplexes with high up‐conversion efficiency. [ABSTRACT FROM AUTHOR]

Phosphorescent manganese(II) complexes with high photoluminescence quantum yields (PLQYs) and low cost exhibit great potential in organic light‐emitting diodes (OLEDs), information security, and X‐ray imaging. However, it is still a challenge to tune their emission colors. Herein, an effective strategy for engineering the phosphorescence colors of tetrahedral Mn(II) complexes through steric hindrance‐driven bond angle distortion is proposed. Modulating the steric hindrance between phosphine and benzofuran and varying the O─Mn─O bond angles allows these Mn(II) complexes to emit from 498 to 548 nm. Interestingly, these achiral single crystals of Mn(II) complexes exhibit significant circularly polarized luminescence signals due to symmetry breaking. Furthermore, high‐performance green OLEDs are achieved by using these Mn(II) complexes as dopants, providing a record‐high external quantum efficiency of 15.7%. These super‐duper results greatly inspire the development of multi‐color Mn(II) complexes and low‐cost Mn‐based devices. [ABSTRACT FROM AUTHOR]