High-performance
pure-red perovskite light-emitting diodes (PeLEDs)
with luminescence peaks around 630 nm are desirable for displays,
yet the brightness and operational stability remain critical factors
limiting their applications. Here, we report the high-luminance and
long-life pure-red PeLEDs achieved by 4-fluorobenzenesulfonamide (4-FBSA)
anchored CsPb(Br/I)3 nanocrystals (NCs). Theoretical simulation
and experimental results confirm the p-π conjugated moiety,
and electronegative atoms weaken the capability of nitrogen atoms
to accept foreign protons, allowing 4-FBSA to act as an L-type ligand
under the acid-amine circumstance and strongly coordinate with NC
surface. The firmly bonded 4-FBSA not only passivates the surface
defects but also enhances the luminescence stability of NCs. The resultant
device exhibits a remarkable luminance of 21 590 cd m–2, a peak efficiency of 21.8%, and an extended half-lifetime of 11.7
h with negligible spectral shifting and broadening during operation,
signifying the advancement of the Rec.2020 pure-red PeLEDs with mix-halide
perovskite emitters toward display applications.