Highly Efficient Quasi 2D Blue Perovskite Electroluminescence Leveraging a Dual Ligand Composition
Highly Efficient Quasi 2D Blue Perovskite Electroluminescence Leveraging a Dual Ligand Composition
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DOI：
10.1002/adfm.202214315
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发表时间：
2023-04-06
影响因子：
19
通讯作者：
Zakhidov, Anvar A.
中科院分区：
文献类型：
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作者：
Alahbakhshi, Masoud;Mishra, Aditya;Zakhidov, Anvar A.
由于其优越的上级外量子效率（EQE）和色纯度，Percent发光二极管（PeLED）正在发展。尽管如此，蓝色PeLED需要额外的工作来实现与其他可见颜色相同的基准。该研究证明了一种非常有效的蓝色PeLED，其峰值发射为488 nm，最大亮度为8600 cd m（-2），并且通过将双面乙烷-1，2-溴化二铵（EDBr 2）配体盐沿着与长链配体甲基苯基氯化铵（MeCl）结合，最大EQE为12.2%。EDBr 2通过减少弱的货车德瓦尔斯相互作用并产生Dion-Jacobson（DJ）结构，成功地改善了2D钙钛矿层之间的相互作用。而原始样品（没有EDBr 2）被小的堆叠数（n）2D相抑制，具有降低PeLED性能的非辐射复合区域，添加EDBr 2成功地实现了从小n相到大n相的更好的能量转移。如通过光致发光（PL）、扫描电子显微镜（SEM）和原子力显微镜（AFM）表征所证明的，EDBr 2通过减少针孔和钝化缺陷来改善形态，随后改善准2D蓝色PeLED的效率和操作寿命。
Perovskite light-emitting diodes (PeLEDs) are advancing because of their superior external quantum efficiencies (EQEs) and color purity. Still, additional work is needed for blue PeLEDs to achieve the same benchmarks as the other visible colors. This study demonstrates an extremely efficient blue PeLED with a 488 nm peak emission, a maximum luminance of 8600 cd m(-2), and a maximum EQE of 12.2% by incorporating the double-sided ethane-1,2-diammonium bromide (EDBr2) ligand salt along with the long-chain ligand methylphenylammonium chloride (MeCl). The EDBr2 successfully improves the interaction between 2D perovskite layers by reducing the weak van der Waals interaction and creating a Dion-Jacobson (DJ) structure. Whereas the pristine sample (without EDBr2) is inhibited by small stacking number (n) 2D phases with nonradiative recombination regions that diminish the PeLED performance, adding EDBr2 successfully enables better energy transfer from small n phases to larger n phases. As evidenced by photoluminescence (PL), scanning electron microscopy (SEM), and atomic force microscopy (AFM) characterization, EDBr2 improves the morphology by reduction of pinholes and passivation of defects, subsequently improving the efficiencies and operational lifetimes of quasi-2D blue PeLEDs.