Li Lok-Kwan, Kwok Wing-Kei, Tang Man-Chung, Cheung Wai-Lung, Lai Shiu-Lun, Ng Maggie, Chan Mei-Yee, Yam Vivian Wing-Wah
Institute of Molecular Functional Materials, Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
Chem Sci. 2021 Nov 2;12(44):14833-14844. doi: 10.1039/d1sc03690d. eCollection 2021 Nov 17.
A new class of C^C^N ligand-containing carbazolylgold(iii) dendrimers has been designed and synthesized. High photoluminescence quantum yields of up to 82% in solid-state thin films and large radiative decay rate constants in the order of 10 s are observed. These gold(iii) dendrimers are found to exhibit thermally activated delayed fluorescence (TADF), as supported by variable-temperature emission spectroscopy, time-resolved photoluminescence decay and computational studies. Solution-processed organic light-emitting diodes (OLEDs) based on these gold(iii) dendrimers have been fabricated, which exhibit a maximum current efficiency of 52.6 cd A, maximum external quantum efficiency of 15.8% and high power efficiency of 41.3 lm W. The operational stability of these OLEDs has also been recorded, with the devices based on zero- and second-generation dendrimers showing maximum half-lifetimes of 1305 and 322 h at 100 cd m, respectively, representing the first demonstration of operationally stable solution-processed OLEDs based on gold(iii) dendrimers.
一类新型含C^C^N配体的咔唑基金（III）树枝状大分子已被设计并合成。在固态薄膜中观察到高达82%的高光致发光量子产率以及约10 s量级的大辐射衰减速率常数。通过变温发射光谱、时间分辨光致发光衰减和计算研究表明，这些金（III）树枝状大分子表现出热激活延迟荧光（TADF）。基于这些金（III）树枝状大分子制备了溶液处理的有机发光二极管（OLED），其最大电流效率为52.6 cd A，最大外量子效率为15.8%，高功率效率为41.3 lm W。还记录了这些OLED的工作稳定性，基于零代和二代树枝状大分子的器件在100 cd m下的最大半衰期分别为1305和322 h，这代表了基于金（III）树枝状大分子的溶液处理OLED首次实现了工作稳定。
