Advancing Scalability and Sustainability of Perovskite Light-Emitting Diodes Through the Microwave Synthesis of Nanocrystals

In recent years, perovskite light-emitting diodes have witnessed a remarkable evolution in both efficiency and luminance levels. Nonetheless, the production of such devices typically relies on protracted synthesis procedures at elevated temperatures and vacuum/inert conditions (e.g. hot-injection synthesis), thus rendering them technically unsuitable for extensive display and/or lighting applications manufacturing. Although alternative synthetic protocols have been proposed, e.g. ligand-assisted reprecipitation, ultrasonic and microwave-based methods, their suitability for the construction of high-performing light-emitting diodes has been reported in only a few studies. In this study, we demonstrate the fabrication of highly efficient lighting devices based on CsPbBr₃ colloidal perovskite nanocrystals synthesized by a fast, energetically efficient, and up-scalable microwave-assisted method. These nanocrystals exhibit an impressive photoluminescence quantum yield of 66.8% after purification, with a very narrow PL spectrum centered at 514 nm with a full width at half-maximum of 20 nm. Similarly, the PeLEDs achieve a maximum external quantum efficiency of 23.4%, a maximum current efficiency of 71.6 Cd A⁻¹, and a maximum luminance level that exceeds 4.7 × 10⁴ Cd m⁻². Additionally, a significantly lower energy consumption for microwave-mediated synthesis compared with hot injection is demonstrated. These findings suggest that this synthetic procedure emerges as an outstanding and promising method towards a scalable and sustainable fabrication of high-quality perovskite light-emitting diodes.