An unreported unprecedented spike of ∼μs line-width, followed by an overshoot, was discovered at the rising edge of transient electroluminescence (TEL) from guest-doped organic light-emitting diodes with strong electron-donating abilities from the host carbazole groups. By changing the device structures and TEL measurement parameters, a series of experimental results demonstrate that this TEL spike is not related to exciton interactions such as singlet–triplet and triplet–triplet annihilations but originated from the radiative recombination of pre-stored electrons with injected holes. Surprisingly, these pre-stored guest electrons do not come from the energy-level traps in the host–guest systems; instead, the guest molecules receive the electrons transferred from the host carbazole groups due to their strong electron-donating abilities. Moreover, the observed spikes show rich and extraordinary temperature dependences. Based on the detailed understanding of the spike formation mechanism, we have proposed the requirements for the occurrence of spike and realized the artificial adjustments of the spike intensity. For instance, the instantaneous luminescent intensity of this spike can reach over 80 times the magnitude of the TEL plateau. Accordingly, this work deepens the physical understanding of this novel spike in TEL and paves the way for fabricating an electro-optic sensor to detect instantaneous weak current signals.

中文翻译：

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来自具有主体咔唑基团强给电子能力的客体掺杂 OLED 的电致发光开启瞬变史无前例的尖峰

在瞬态电致发光 (TEL) 的上升沿发现了一个未报告的 ∼μs 线宽的史无前例的尖峰，其来自主体咔唑基团具有强给电子能力的客体掺杂有机发光二极管。通过改变器件结构和 TEL 测量参数，一系列实验结果表明，这种 TEL 尖峰与激子相互作用（如单线态-三线态和三线态-三线态湮灭）无关，而是源于预先存储的电子与注入空穴的辐射复合. 令人惊讶的是，这些预先存储的客体电子并非来自主客体系统中的能级陷阱；相反，客体分子由于其强大的给电子能力而接收从主体咔唑基团转移的电子。而且，观察到的尖峰显示出丰富而非凡的温度依赖性。在详细了解尖峰形成机理的基础上，提出了尖峰发生的要求，实现了尖峰强度的人为调节。例如，这个尖峰的瞬时发光强度可以达到 TEL 平台的 80 倍以上。因此，这项工作加深了对 TEL 中这种新型尖峰的物理理解，并为制造电光传感器以检测瞬时弱电流信号铺平了道路。例如，这个尖峰的瞬时发光强度可以达到 TEL 平台的 80 倍以上。因此，这项工作加深了对 TEL 中这种新型尖峰的物理理解，并为制造电光传感器以检测瞬时弱电流信号铺平了道路。例如，这个尖峰的瞬时发光强度可以达到 TEL 平台的 80 倍以上。因此，这项工作加深了对 TEL 中这种新型尖峰的物理理解，并为制造电光传感器以检测瞬时弱电流信号铺平了道路。