Efficient green light-emitting diodes based on quasi-two-dimensional composition and phase engineered perovskite with surface passivation.
Efficient green light-emitting diodes based on quasi-two-dimensional composition and phase engineered perovskite with surface passivation.
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基于准二维成分和表面钝化相工程钙钛矿的高效绿色发光二极管
DOI：
10.1038/s41467-018-02978-7
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发表时间：
2018-02-08
影响因子：
16.6
通讯作者：
You J
中科院分区：
文献类型：
--
作者：
Yang X;Zhang X;Deng J;Chu Z;Jiang Q;Meng J;Wang P;Zhang L;Yin Z;You J
发光二极管（LED）由于其高效、窄的发光范围而引起人们的极大关注。具有Ruddlesden-Popper型层状结构的准二维钙钛矿可以增大激子结合能并限制电荷载流子，被认为是高效LED的良好候选材料。然而，这些材料通常含有相的混合物，并且相杂质可能导致低的发射效率。此外，将三维钙钛矿转化为准二维钙钛矿由于晶体尺寸的减小而在表面或晶界处引入更多的缺陷。这两个因素都限制了LED的发光效率。在这里，首先，通过成分和相位工程，选择最佳的准二维钙钛矿。其次，通过在钙钛矿薄膜表面涂覆有机小分子三辛基氧化膦进行表面钝化。因此，基于准二维钙钛矿的绿色LED达到62.4 cd A-1的电流效率和14.36%的外量子效率。可溶液加工的卤化物钙钛矿具有高发光效率和优异的化学可调谐性，使其成为发光二极管的理想候选者。在这里，Yang等人通过微调相位和钝化表面缺陷，在器件中实现了14%的高外量子效率。
Perovskite light-emitting diodes (LEDs) are attracting great attention due to their efficient and narrow emission. Quasi-two-dimensional perovskites with Ruddlesden–Popper-type layered structures can enlarge exciton binding energy and confine charge carriers and are considered good candidate materials for efficient LEDs. However, these materials usually contain a mixture of phases and the phase impurity could cause low emission efficiency. In addition, converting three-dimensional into quasi-two-dimensional perovskite introduces more defects on the surface or at the grain boundaries due to the reduction of crystal sizes. Both factors limit the emission efficiency of LEDs. Here, firstly, through composition and phase engineering, optimal quasi-two-dimensional perovskites are selected. Secondly, surface passivation is carried out by coating organic small molecule trioctylphosphine oxide on the perovskite thin film surface. Accordingly, green LEDs based on quasi-two-dimensional perovskite reach a current efficiency of 62.4 cd A−1 and external quantum efficiency of 14.36%. Solution-processable halide perovskites have high luminous efficiency and excellent chemical tunability, making them ideal candidates for light-emitting diodes. Here Yang et al. achieve high external quantum efficiency of 14% in the devices by fine-tuning the phase and passivating the surface defects.
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影响因子：
35
作者：
Pimputkar, Siddha;Speck, James S.;Nakamura, Shuji
通讯作者：
Nakamura, Shuji
影响因子：
5.7
作者：
Deschler, Felix;Price, Michael;Friend, Richard H.
通讯作者：
Friend, Richard H.
影响因子：
15
作者：
Quan, Li Na;Yuan, Mingjian;Sargent, Edward H.
通讯作者：
Sargent, Edward H.
影响因子：
10.8
作者：
Protesescu L;Yakunin S;Bodnarchuk MI;Krieg F;Caputo R;Hendon CH;Yang RX;Walsh A;Kovalenko MV
通讯作者：
Kovalenko MV
50倍%20EQE%20改善%20up%20to%206.27%%20of%20溶液处理%20全无机%20%20%20%20%20%20钙钛矿%20CsPbBr3%20QLEDs%20via%20Surface%20Ligand%20Density%20Control
影响因子：
29.4
作者：
Li, Jianhai;Xu, Leimeng;Zeng, Haibo
通讯作者：
Zeng, Haibo