Poor stability as an essential issue of metal halide perovskites (MHPs), limits their further applications in displaying and lighting. Among multicolor luminous MHPs, the development of blue luminous perovskite lags far behind that of red and green emission. Herein, a “MAPbBr_xCl_3-x quantum dots (QDs) in Pb(OH)Br” strategy is proposed, fabricating stable MAPbBr_xCl_3-x@Pb(OH)Br with the emission wavelength of 435–485 nm. Experimental characterizations indicate that cubic MAPbBr_xCl_3-x transforms into rectangular MAPbBr_xCl_3-x@Pb(OH)Br with the assistance of methylamine vapor. The as-prepared MAPbBr_xCl_3-x@Pb(OH)Br shows high stability of water, light, heat and organic solvents, which can emit bright emission even they are immersed in water for 6 months. In addition, anion exchange induced spectral shift of the MHPs are also suppressed due to the chemical inertness of Pb(OH)Br. Notably, this strategy is also applied to all inorganic halide perovskites. Blue light-emitting devices (LEDs) based on the MAPbBr_xCl_3-x@Pb(OH)Br have been demonstrated, which can run stably for over 8 h with brightness exceeding 1000 cd/m² in a humid environment.

差的稳定性作为金属卤化物钙钛矿（MHP）的基本问题，限制了它们在显示和照明中的进一步应用。在多色发光MHP中，蓝色钙钛矿发光的发展远远落后于红色和绿色发光。在本文中，提出了“ Pb（OH）Br中的MAPbBr _x Cl _3-x量子点（QDs）”策略，以发射波长为435-485 nm的稳定MAPbBr _x Cl _3-x @Pb（OH）Br。实验表征表明，立方甲基MAPbBr _x Cl _3-x在甲胺蒸气的帮助下转变为矩形MAPbBr _x Cl _3-x @Pb（OH）Br。制备的MAPbBr _x Cl_3-x @Pb（OH）Br显示出对水，光，热和有机溶剂的高度稳定性，即使将它们浸入水中6个月也可以发出明亮的光。此外，由于Pb（OH）Br的化学惰性，也抑制了MHP的阴离子交换引起的光谱移动。值得注意的是，该策略也适用于所有无机卤化物钙钛矿。已经证明基于MAPbBr _x Cl _3-x @Pb（OH）Br的蓝色发光器件（LED）可以在潮湿环境中稳定运行8小时以上，亮度超过1000 cd / m ²。