Short-Wavelength Infrared Organic Light-Emitting Diodes from Solution-Processable Aggregation-Induced Emission Molecules.

Short-wavelength-infrared (SWIR) organic light-emitting diodes (OLEDs) have clearly demonstrated advantageous mechanical flexibility and biocompatibility, making them potentially useful in many applications, such as bioimaging, food inspection, sensors, and human-compatible electronics. However, the performance of present pure organic semiconductors in the SWIR spectral region is hindered by their low luminescence efficiency, a phenomenon primarily attributable to strong aggregation-caused emission quenching. Here, we demonstrate the use of solution-processable aggregation-induced emission (AIE) molecules as the emitting layer for high-performance SWIR OLEDs. We tailor the exciton generation zone inside the device to achieve an improved charge balance factor and light outcoupling efficiency through the introduction of an electron-blocking layer beneath the AIE-emitting layer. The resulting device exhibits an emission peak at 1000 nm with a maximum external quantum efficiency of 0.10% and a maximum radiant exitance of 3.41 mW cm, representing one of the best performances among solution-processable SWIR OLEDs. Additionally, the device achieves an operational half-lifetime of 2 h at a high current density of 2200 mA cm with a high initial irradiance of 2.39 mW cm in ambient air, indicating stable device characteristics for practical applications. Our results establish a solid foundation for a new family of SWIR OLEDs, promising a broad range of applications.