Nanoporous Scaffold‐Assisted Ligand‐Free CsPbBr ₃ Quantum Dots for Bright and Ultrapure Green Light‐Emitting Diodes

The development of stable and spectrally pure green emitters remains a critical challenge for high performance full color displays and solid‐state lighting. In this work, we present a simple and effective approach to fabricate perovskite light‐emitting diodes based on CsPbBr 3 quantum dots confined within a nanoporous silica scaffold. The introduction of linear (n) or branched (t) butylammonium bromide and crown ethers into the precursor solution prior to infiltration induces improved charge injection and transport across the active layer. This dual‐additive approach contributes to a dramatic enhancement in device performance, leading to a highest luminance exceeding 10,000 cd m − 2 , and markedly improved operational stability. The optimized devices exhibit ultrapure green emission centered at 520 nm with a narrow spectral width below 20 nm. The proposed method provides a versatile and scalable route toward bright, spectrally pure, and durable perovskite light‐emitting devices.