Near-infrared (NIR) to visible light upconversion is of significant importance in many applications, including thermal imaging, bioimaging, night vision, and wellness monitoring. Here, the effort to develop a high-performing NIR to saturated green light upconversion device comprising a front solution-processable organic bulk heterojunction NIR charge generation layer (CGL) and an upper CsPbBr3 perovskite light-emitting diode (LED) unit is reported. The NIR CGL, based on a blend of the NIR-sensitive donor polymer and a nonfullerene acceptor, enables an efficient hole injection in the CsPbBr3 LED in the presence of the NIR light and also serves as an optical outcoupling layer to enhance the visible light emission by the CsPbBr3 LED. The CsPbBr3-based perovskite LED has a narrow emission spectrum with a peak wavelength of 520 nm, corresponding to the wavelengths near the peak response of the human eye, and has the advantage in imaging applications. Based on the upconversion process, a pixel-less NIR to visible light imaging device is demonstrated, which can be operated at a low voltage of 3 V. The results are very encouraging, revealing a high-performing solution-processable upconversion device for application in NIR light imaging.
Scopus Subject Areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- NIR imaging
- NIR to visible light upconversion
- nonfullerene acceptor
- perovskite light-emitting diode