Perovskite nanocrystals (PNCs) are ideal for optical devices due
to their adjustable emission band and high photoluminescence. However,
blue light-emitting perovskite nanocrystals (PNCs) exhibit poor performance
compared to their green and red-emitting PNC counterparts. Herein,
we introduce a simple strategy for increasing the stability of blue
light-emitting CsPb (Br/Cl)3 PNCs passivated with an Al-doped
CdSe layer. This simple strategy successfully achieves highly stable
PNCs with photoluminescence (PL) emission ranging from 454 to 460
nm with a full width at half-maximum (FWHM) ranging from 18 to 22
nm; changes in bandgaps are also observed, and the corresponding PLQY
values show a significant change after CdSe/Al modification. In addition,
CsPb (Br/Cl)3 PNCs with a CdSe layer doped with Al formed
on the surface show remarkable stability under ambient conditions,
including thermal exposure, water resistance, and ultraviolet (UV)
irradiation. A light-emitting diode (LED) device was constructed to
demonstrate the feasibility of the approach by combining the optimal
CsPb(Br/Cl)3/CdSe/Al PNCs with an existing commercial 365
nm UV chip, resulting in bright blue light emission with CIE color
coordinates of (0.16, 0.09). All of the findings suggest that doped
CsPb (Br/Cl)3/CdSe/Al PNCs have the potential to be used
as color converters in liquid crystal displays (LCDs).