1 research outputs found
Surface Reconstruction of CsPbBr<sub>3</sub> Nanocrystals by the Ligand Engineering Approach for Achieving High Quantum Yield and Improved Stability
Oleylamine/oleic acid (OAm/OA) as the commonly used ligand
is indispensable
in the synthesis of perovskite nanocrystals (PNCs). Unfortunately,
poor colloidal stability and unsatisfactory photoluminescence quantum
yield (PLQY) are observed, resulting from a highly dynamic binding
nature between ligands. Herein, we adopt a facile hybrid ligand (DDAB/ZnBr2) passivation strategy to reconstruct the surface chemistry
of CsPbBr3 NCs. The hybrid ligand can detach the native
surface ligand, in which the acid–base reactions between ligands
are suppressed effectively. Also, they can substitute the loose capping
ligand, anchor to the surface firmly, and supply sufficient halogens
to passivate the surface trap, realizing an exceptional PLQY of 95%
and an enhanced tolerance toward ambient storage, UV irradiation,
anti-solvents, and thermal treatment. Besides, the as-fabricated white
light-emitting diode (WLED) utilizing the PNCs as the green-emitting
phosphor has a luminous efficiency around 73 lm/W; the color gamut
covers 125% of the NTSC standard