Enhanced Luminescent Performance Via Passivation of Surface Undercoordinated Pb Atoms in a CsPbBr3 Microplate

AbstractPerovskite materials are widely used in the fields of luminescence and light energy conversion with the advantages of low cost and outstanding optoelectronic properties. However, abundant surface lattice defects heavily affect the performances of perovskite optoelectronic devices. Here, by treating surface defects with oleylamine molecules in situ, the surface trap states are significantly decreased in a CsPbBr3 microplate, enabling photoluminescence intensity and carrier lifetimes to be dramatically enhanced and prolonged, respectively. These interesting phenomena can be attributed to the binding of undercoordinated Pb atoms with N atoms on the surface of perovskite microplate. The strong binding energy of lead‐halogen bonds inhibits the photodegraded reactions of the crystal, leading to the significant improvement of luminescent stability for the microplate correspondingly. The results not only provide experimental guidance for passivating lattice defects but also pave the way for improving the efficiency of wide materials and optoelectronic devices.