Abstract Near ultraviolet organic light-emitting diodes (NUV-OLEDs) have a wide range of applications. However, when large band-gap polymer of PVK was used as the emitting material, its poor electron transportation capability resulted in a large amount of charge accumulation on both sides of light-emitting layer/electron-transporting layer interface of the device, hence generating intense electroplex emission and seriously reducing the efficiency of NUV light-emitting. In order to solve this issue, BCPO molecules were doped in PVK with certain concentrations, forming PVK:BCPO mixing light-emitting layers. As compared with pure PVK, electron transportation capability was apparently increased in PVK:BCPO mixing layers. On one hand, charge accumulation at the interface was substantially weakened, and the electroplex emission was inhibited. On the other hand, transportations of electron and hole carriers became more balanced in light-emitting layer. Both of these improvements effectively promoted device performance. At appropriate BCPO doping concentration, the external quantum efficiency of PVK:BCPO-based NUV-OLEDs reached the maximum value of ∼2.6 %. Further experimental progress would bring it closer to the practical application in future.

中文翻译：

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基于掺杂 BCPO 分子的 PVK 材料的高效近紫外有机发光二极管

摘要 近紫外有机发光二极管（NUV-OLED）有着广泛的应用。然而，当PVK的大带隙聚合物作为发光材料时，其电子传输能力差，导致器件发光层/电子传输层界面两侧有大量电荷积累，从而产生强烈的电子复合物发射并严重降低 NUV 发光效率。为了解决这个问题，将BCPO分子按一定浓度掺入PVK中，形成PVK:BCPO混合发光层。与纯 PVK 相比，PVK:BCPO 混合层中的电子传输能力明显增加。一方面，界面处的电荷积累显着减弱，电复合物发射受到抑制。另一方面，发光层中电子和空穴载流子的传输变得更加平衡。这两项改进都有效地提升了设备性能。在适当的 BCPO 掺杂浓度下，基于 PVK:BCPO 的 NUV-OLED 的外量子效率达到最大值~2.6%。进一步的实验进展将使其更接近未来的实际应用。