The CsPbBr₃@Cs₄PbBr₆ nanocrystals (NCs) could be synthesized by multiple Cs-oleate injections as adding the 1,9-dibromnonane in the reaction solution. The 1,9-dibromnonane could provide Br⁻ ions and the rich Br⁻ ions effectively restrain the generation of CsBr. The Cs₄PbBr₆ wrapped around the CsPbBr₃ NCs and the size of crystalline grain was increased with increasing the Cs-oleate as excess oleylamine. The quantum yield for 14S4DN reached to 99.3 % due to the decrease of defects and the surface passivation of Cs₄PbBr₆. There are more oleylammonium bromide on the surface of CsPbBr₃ NCs as synthesized with 1,9-dibromnonane. The ligand shell and the surface passivation of Cs₄PbBr₆ restrained the decomposition of surface, consequently improved the stability of moisture and light for CsPbBr₃ NCs. When the CsPbBr₃@Cs₄PbBr₆ NCs were immersed in water under UV light (365 nm) for 2 h, the PL intensity could retain 90.4 %, while the 11S1 (traditional CsPbBr₃ NCs) was only 10.9 %. It indicated the stability of moisture and light for CsPbBr₃ NCs were greatly improved, because Cs₄PbBr₆ NCs effectively passivated the surface of CsPbBr₃ NCs and restrained the generation of traps states.

在反应溶液中加入1,9-二溴壬烷可以通过多次注入油酸铯来合成CsPbBr ₃ @Cs ₄ PbBr ₆纳米晶体（NCs）。1,9- dibromnonane可以提供溴^-离子和丰富的溴^-离子有效地抑制溴化铯的产生。Cs ₄ PbBr ₆包裹在CsPbBr ₃ NCs周围，晶粒尺寸随着Cs-​​油酸酯作为过量的油胺的增加而增加。由于缺陷的减少和Cs ₄ PbBr ₆的表面钝化，14S4DN的量子产率达到99.3％。CsPbBr的表面上存在更多的溴化乙锭用1,9-二溴壬烷合成_3个NC。Cs ₄ PbBr ₆的配体壳层和表面钝化抑制了表面的分解，因此提高了CsPbBr ₃ NCs的水分和光的稳定性。将CsPbBr ₃ @Cs ₄ PbBr ₆ NCs浸入水中（365 nm）2 h，PL强度可保持90.4％，而11S1（传统CsPbBr ₃ NCs）仅为10.9％。这表明由于Cs ₄ PbBr ₆ NC有效地钝化了CsPbBr ₃的表面，大大提高了CsPbBr ₃ NC的水分和光的稳定性。 NC和限制陷阱状态的生成。