Stable and Efficient Green Perovskite Nanocrystal-Polysilazane Films for White LEDs Using an Electrospray Deposition Process.
Stable and Efficient Green Perovskite Nanocrystal-Polysilazane Films for White LEDs Using an Electrospray Deposition Process.
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DOI：
10.1021/acsami.9b04164
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发表时间：
2019-05
影响因子：
9.5
通讯作者：
Hee Chang Yoon;Y. Do
中科院分区：
文献类型：
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作者：
Hee Chang Yoon;Y. Do
我们通过电喷雾（e-spray）沉积硅氮烷（SZ）低聚物修饰的钙钛矿纳米晶体（PeNC）溶液，在Si-N/ si基聚硅氮烷（PSZ）基体上封装一步，成功制备了稳定、高效、易用的CsPbBr3钙钛矿纳米晶体（PeNC）嵌入无机聚合物薄膜。为了消除配体从PeNC表面剥离时产生的Pb2+缺陷位点，可以通过将SZ寡聚物（孤对的供体）与Pb2+位点（孤对的受体）偶联来实现刘易斯酸/碱加合物的表面钝化。加入SZ寡聚物后，光降解CsPbBr3 PeNC的光致发光量子产率恢复到原来的2.35倍，稳定性较未处理的CsPbBr3 PeNC溶液明显提高。在电子喷雾沉积过程中，经sz处理的CsPbBr3 PeNC溶液液滴与大气水分发生聚合反应，通过溶胶-凝胶反应形成Si-N/Si-O网络包封剂。所得的CsPbBr3-PSZ薄膜在大多数环境条件下都表现出更高的稳定性，包括空气储存、蓝光暴露、紫外线暴露、热暴露和水浸泡。优化后的CsPbBr3-PSZ薄膜覆盖蓝色发光二极管（LED）表现出良好的性能，发光效率（LE）为85.9 lm/W，色蓝转换效率（CE）为60.1%。此外，这种易于使用的CsPbBr3-PSZ薄膜可以与红色发射的K2SiF6:Mn4+/硅树脂薄膜结合，实现远程型白-蓝LED。在相关色温为9334 K时，白光LED的发光效率（LE）和发光效率（CE）分别为71.0 lm/W和50.8%，在长期工作100 h时，发光效率（CE）仅下降8%。这一结果表明，电子喷雾沉积是一种简单的制造工艺，可以利用液滴与空气中的水分之间的快速溶胶-凝胶反应，从不稳定的PeNC溶液中制备稳定高效的PeNC薄膜。
We successfully fabricated a stable, efficient, and easy-to-use CsPbBr3 perovskite nanocrystal (PeNC)-embedded inorganic polymer film through an encapsulation step with a Si-N/Si-O-based polysilazane (PSZ) matrix via the electrospray (e-spray) deposition of a silazane (SZ) oligomer-decorated PeNC solution. To eliminate Pb2+ defect sites that are generated when the ligands are peeled from the PeNC surface, surface passivation of the Lewis acid/base adduct is possible by coupling the SZ oligomer (the donor of lone pairs) with Pb2+ sites (the acceptor of lone pairs). With the addition of the SZ oligomer, the photoluminescence quantum yield of photodegraded CsPbBr3 PeNC was recovered and increased by 2.35-fold whereas the stability was improved significantly from an untreated CsPbBr3 PeNC solution. During the e-spray deposition process, SZ-treated CsPbBr3 PeNC solution droplets can react with atmospheric moisture to polymerize and form a Si-N/Si-O network encapsulant via a sol-gel reaction. The resultant CsPbBr3-PSZ films showed improved stability levels under most environmental conditions, including air storage, blue light exposure, UV exposure, thermal exposure, and water immersion. The optimum CsPbBr3-PSZ film-covered blue light-emitting diode (LED) showed good performance capabilities, with a luminous efficacy (LE) of 85.9 lm/W and color-by-blue conversion efficiency (CE) of 60.1%. Furthermore, this easy-to-use CsPbBr3-PSZ film can be employed to realize a remote-type white-by-blue LED by combining it with red emissive K2SiF6:Mn4+/silicone film. The LE and CE rates of the white LED were 71.0 lm/W and 50.8%, respectively, at a correlated color temperature of 9334 K, with only an 8% drop in the LE for long-term operation of 100 h. This result indicates that e-spray deposition is a simple fabrication process by which to create stable and efficient PeNC films from an unstable PeNC solution using a rapid sol-gel reaction between droplets and moisture from the air.