Thermally Stable Red-Emitting Mixed Halide Perovskite Nanocrystals Enabled by Solid Reaction and Co-Doping Process
Thermally Stable Red-Emitting Mixed Halide Perovskite Nanocrystals Enabled by Solid Reaction and Co-Doping Process
复制标题
DOI：
10.1002/adom.202200751
复制
发表时间：
2022-06-10
影响因子：
9
通讯作者：
Tian，Jianjun
中科院分区：
文献类型：
--
作者：
Tian，Shuyu;Zhou，Xianfeng;Tian，Jianjun
金属卤化物钙钛矿纳米晶（NC）随着温度的升高而快速性能退化，这极大地限制了其在照明和显示领域的实际应用。对于混合卤化物钙钛矿NC，由于严重的离子迁移，该问题甚至更加严重。在此，设计了一种在N2气氛中的固相反应过程，在该过程中获得了具有SiO2壳层的红色发射（631 nm波长）混合卤化物CsPbBr1.5I1.5NC。同时，Zn 2+和K+离子共掺杂到晶格中以提高辐射衰减速率并降低NC的陷阱密度。共掺杂纳米碳的光致发光量子产率达到64.5%，这是通过固相反应获得的混合卤化物钙钛矿纳米碳的最高值之一。重要的是，K+的掺杂剂进入钙钛矿结构的间隙位置以增加结构刚性，这抑制激子-声子相互作用并提高热激活能，从而改善热猝灭抗性以在高温（>353 K）下维持高发射强度。此外，基于NC的红色背光发光二极管在353 K下连续工作700 h后发光强度没有衰减，表现出对于商业应用的显著稳定性。
Rapid performance degradation as temperature increases for metal halide perovskite nanocrystals (NCs) greatly restricts the practical application for lighting and display. This problem is even more grievous for the mixed‐halide perovskite NCs because of severe ions migration. Here, a solid‐reaction process in the N2atmosphere is devised, in which the red‐emitting (631 nm wavelength) mixed halide CsPbBr1.5I1.5NCs with a coating of SiO2shell are achieved. Meanwhile, the Zn2+and K+ions are co‐doped into the crystal lattice to enhance the radiative decay rate and decrease the trap density of the NCs. The photoluminescence quantum yield of the co‐doped NCs reaches 64.5%, which is one of the highest values for the reported mixed‐halide perovskite NCs obtained by the solid reaction. Importantly, the dopant of K+enters into the interstitial position of the perovskite structure to increase the structural rigidity, which inhibits exciton–phonon interaction and elevates thermal activation energy, thus improving thermal quenching resistance to sustain high emission intensity at high temperature (>353 K). Furthermore, the red backlight emitting diode based on the NCs exhibits no decay in luminescence intensity after continuous operation for 700 h at 353 K, representing remarkable stability for the commercial application.