Buried-interface stabilization for efficient and bright blue perovskite LEDs

Metal halide perovskites are highly promising luminescent materials; however, the development of high-performance blue perovskite light-emitting diodes (PeLEDs) remains constrained by buried interface degradation. Here, we construct a three-dimensional cross-linked network of pentaerythritol tetraacrylate on the hole transport layer (HTL) to achieve efficient and bright blue PeLEDs. This dense cross-linked network serves as a physical barrier, shielding the HTL from polar solvent erosion and preserving its structural integrity. The abundant carbonyl groups in the network form strong coordination interactions with the perovskite lattice, effectively passivating interfacial defects and enhancing interfacial stability. Furthermore, an interfacial dipole formed at the HTL/network interface modulates the energy level alignment, facilitating efficient hole injection. The resulting PeLEDs across blue spectral regions deliver outstanding external quantum efficiencies of 28.0% at 488 nm, 21.3% at 476 nm, and 15.4% at 466 nm, with maximum luminance values of 26,240, 10,750, and 2444 cd m^-2, respectively.