Near-infrared organic light-emitting diodes of pure fluorescence emission using small-molecule boron-dipyrromethene derivative

Near-infrared (NIR) light has various applications, such as in cameras and sensors. Organic light-emitting diodes (OLEDs), which are characterized by their thinness, lightweight, and flexibility, have potential application in various devices requiring light emission in the NIR region. In this study, we focused on the wavelength range of 700–1000 nm, which is called the “first optical window” in NIR light. Furthermore, we investigated the optical properties of a low-molecular-weight boron-dipyrromethene derivative (BODIPY-Ph), which has been reported to possess NIR absorption properties as well as the luminescence properties of BODIPY-Ph-based OLEDs in the NIR region. An acetone solution of BODIPY-Ph showed 52.3% photoluminescence quantum yield and the apparent external quantum efficiency of the OLED in the NIR region was high at 1.87%, which is one of the highest values when using OLEDs that are metal-free and use pure fluorescence emission without using triplet.