Qiao Xianfeng, Xiao Shu, Yuan Peisen, Yang Dezhi, Ma Dongge
Institute of Polymer Optoelectronic Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China.
Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China.
Front Optoelectron. 2022 Apr 20;15(1):11. doi: 10.1007/s12200-022-00021-8.
The transient electroluminescence (EL) technique is widely used to evaluate the carrier mobility in the field of organic light emitting diodes. The traditional analog detection strategy using oscilloscopes is generally limited since the background noise causes an underestimation of the mobility value. In this paper, we utilize time-correlated single-photon counting (TCSPC) to probe the transient EL for mobility calculation. The measurements on tris(8-hydroxyquinoline) aluminum (Alq) show that the electron mobilities obtained using the TCSPC technique are slightly higher than those obtained from the analog method at all the investigated voltages. Moreover, the TCSPC mobilities demonstrate weaker dependence on the root of electrical field compared to the oscilloscope mobilities. These improvements are attributed to the unique principle of TCSPC, which quantifies the EL intensity by counting the number of single-photon pulses, improving its single-photon sensitivity and eliminating the negative impacts of electrical noise. These advantages make TCSPC a powerful technique in the characterization of time-resolved electroluminescence.
瞬态电致发光（EL）技术在有机发光二极管领域被广泛用于评估载流子迁移率。使用示波器的传统模拟检测策略通常受到限制，因为背景噪声会导致迁移率值被低估。在本文中，我们利用时间相关单光子计数（TCSPC）来探测瞬态EL以进行迁移率计算。对三（8-羟基喹啉）铝（Alq）的测量表明，在所有研究电压下，使用TCSPC技术获得的电子迁移率略高于通过模拟方法获得的迁移率。此外，与示波器迁移率相比，TCSPC迁移率对电场平方根的依赖性较弱。这些改进归因于TCSPC的独特原理，该原理通过对单光子脉冲数量进行计数来量化EL强度，提高了其单光子灵敏度并消除了电噪声的负面影响。这些优点使TCSPC成为表征时间分辨电致发光的强大技术。
