レビュー
近赤外発光材料の開発とOLEDの高性能化
2021 年 52 巻 1 号 p. 2-9
詳細
2021 年 52 巻 1 号 p. 2-9
Near-infrared (NIR) organic light-emitting diodes (OLEDs) are expected to be applied to medical wearable sensors due to their unique characteristics such as bio-permeability and non-invasiveness of NIR light. However, in conventional NIR OLEDs, the exciton production efficiency remains at 25% in principle when fluorescent emitter molecules are used. In this report, we introduce NIR OLED systems using an efficient singlet exciton fission (SF) process, and a thermally activated delayed fluorescence (TADF) assisted fluorescence (TAF) process toward the realization of highly efficient NIR EL. A sophisticated TAF-OLED showed a very promising performance, i.e., EL peak wavelength = 901 nm, EQE = 1.1%, and lifetime > 600 h. Furthermore, by combining an NIR OLED together with an NIR organic photodiode on-chip, we demonstrate a pulse wave sensing system.
