High luminescence and external quantum efficiency in perovskite quantum-dots light-emitting diodes featuring bilateral affinity to silver and short alkyl ligands
High luminescence and external quantum efficiency in perovskite quantum-dots light-emitting diodes featuring bilateral affinity to silver and short alkyl ligands
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DOI：
10.1016/j.cej.2021.128866
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发表时间：
2021-02-15
影响因子：
15.1
通讯作者：
Kuo, Chi-Ching
中科院分区：
文献类型：
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作者：
Chen, Wei-Cheng;Fang, Yu-Han;Kuo, Chi-Ching
钙钛矿量子点(PeQds)具有优异的光电性能和溶液可加工性，近年来得到了商业化和功能性的发展。然而，PeQds周围的绝缘配体和不稳定性都会影响光电子器件的性能。因此，我们引入了银(银)-三辛基膦(TOP)作为短烷基配体的多步配体交换，以增强PeQD的光学性质和稳定性，并成功地提高了发光二极管的性能。含有AgTOP配体(Ag@QD)的PeQD具有更高的光致发光量子产率(PLQY，-93%)和更高的激子结合能(57.6 meV)，并且在1个月内具有更好的溶剂、温度和环境稳定性，与传统的双十二烷基二甲基溴化铵(DDAB)或顶级配体相比表现出更好的性能。核磁共振(核磁共振)、X射线光电子能谱(XPS)和时间分辨光致发光(tr-PL)测量清楚地揭示了Ag@QD中的双边亲和力，说明了良好的缺陷钝化和适当的空间位阻。此外，我们还发现Ag@QD具有较低的开启电压(-2.8V)、高电致发光(-3820cd/cm(-2))和高效率(EQE-9.43%)。
Perovskite quantum dots (PeQDs) have been under commercial and functional development in recent years since they offer outstanding optoelectronic properties and solution processability. However, both insulating ligands around PeQDs and instability impair the performance of photoelectronic devices. Therefore, we introduce multistep ligands exchange by silver (Ag)- trioctylphosphine (TOP) as short alkyl ligands to reinforce the optical properties and stability for PeQDs and successfully elevated light-emitting diodes characters. The PeQDs with AgTOP ligands (Ag@QD) perform higher photoluminescence quantum yield (PLQY, -93%), higher exciton binding energy (57.6 meV) with better solvent, temperature, and ambient stability over 1 month presenting better performances on comparison with conventional di-dodecyl dimethyl ammonium bromide (DDAB) or TOP ligands. Nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and time-resolved photoluminescence (TR-PL) measurement provides clear insight on bilateral affinity in Ag@QD illustrating excellent defect passivation and appropriate steric hindrance. Furthermore, we demonstrate Ag@QD with lower turn-on voltage (-2.8 V), high electroluminescence (-3820 cd/cm(-2)), and high efficiency (EQE - 9.43%).