Iso Yoshiki, Eri Momoko, Hiroyoshi Risako, Kano Kensho, Isobe Tetsuhiko
Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
R Soc Open Sci. 2022 Aug 24;9(8):220475. doi: 10.1098/rsos.220475. eCollection 2022 Aug.
CsPb(Br,I) quantum dots (QDs) show application potential for optoelectronic devices. However, their thermal degradation is a significant problem. In this work, the effects of perfluorodecanoic acid (PFDA) modification on the photoluminescence (PL) and thermal resistance of CsPb(Br,I) QDs were evaluated. The PL intensity of oleic-acid-modified quantum dots (OA-QDs) in toluene decreased drastically upon heating at 100°C. The PL quantum yield of the QDs increased from 69.6% to 77.4% upon modification with PFDA. Furthermore, the PL intensity of the QDs modified with PFDA (PFDA-QDs) increased to 140.6% upon heating, because of the reduction of surface defects upon adsorption of PFDA and its optimized adsorption state. A solid-film PFDA-QDs sample heated at 80°C for 4 h showed temporary PL enhancements for the OA-QDs and PFDA-QDs films to 445% and 557% of their initial values, respectively, upon heating for 0.25 h. This was attributed to the optimized adsorption states of the surface ligands. PFDA-QDs film maintained 354% after 4 h of heating, whereas that of OA-QDs film was 104%. Thus, PFDA modification enhances PL intensity and suppresses PL degradation under heating, which is important for wavelength converters for optoelectronic device applications.
CsPb(Br,I)量子点（QDs）在光电器件方面展现出应用潜力。然而，它们的热降解是一个重大问题。在这项工作中，评估了全氟癸酸（PFDA）修饰对CsPb(Br,I)量子点的光致发光（PL）和热稳定性的影响。油酸修饰的量子点（OA-QDs）在甲苯中的PL强度在100°C加热时急剧下降。用PFDA修饰后，量子点的PL量子产率从69.6%提高到77.4%。此外，由于PFDA吸附后表面缺陷减少及其优化的吸附状态，PFDA修饰的量子点（PFDA-QDs）在加热时PL强度增加到140.6%。在80°C加热4小时的固态薄膜PFDA-QDs样品，对于OA-QDs和PFDA-QDs薄膜，在加热0.25小时后，其PL分别暂时增强到初始值的445%和557%。这归因于表面配体的优化吸附状态。加热4小时后，PFDA-QDs薄膜保持在354%，而OA-QDs薄膜为104%。因此，PFDA修饰增强了PL强度并抑制了加热下的PL降解，这对于光电器件应用的波长转换器很重要。
