Facile Synthesis of Stable and Highly Luminescent Methylammonium Lead Halide Nanocrystals for Efficient Light Emitting Devices
Facile Synthesis of Stable and Highly Luminescent Methylammonium Lead Halide Nanocrystals for Efficient Light Emitting Devices
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DOI：
10.1021/jacs.8b09706
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发表时间：
2019-01-23
影响因子：
15
通讯作者：
Snaith, Henry J.
中科院分区：
文献类型：
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作者：
Hassan, Yasser;Ashton, Olivia J.;Snaith, Henry J.
金属卤化物钙钛矿是用于发光二极管（LED）的有希望的候选者，这是由于它们具有颜色可调谐和高发光效率的潜力。虽然基于钙钛矿的发光二极管的最新进展已经导致绿色发射体的外部量子效率超过12.4%，并且基于3D/2D混合维度钙钛矿的红外发射体已经超过20%，但是红色和蓝色发射体的外部量子效率仍然落后。迄今为止的关键问题是产生具有期望的发射带隙的高发射性和稳定的钙钛矿发射体，以实现全色显示器和白色LED。在这里，我们报告的制备和表征的高度发光和稳定的悬浮液的三碘化甲基铵铅（CH 3 NH3 PbI 3）钙钛矿纳米晶体，其中我们合成的纳米晶体通过配体辅助再沉淀技术，使用乙腈/甲胺化合物溶剂系统溶剂化的离子和甲苯作为反溶剂诱导结晶。通过调节配体的比例、配体与甲苯的比例以及甲苯的温度，我们获得了光致发光量子产率超过93%，发射波长在660 ~ 705 nm之间可调的CH 3 NH3 PbI 3纳米晶溶液。我们还实现了红色发射在635 nm处通过混合的纳米晶体与溴化物盐，并获得了钙钛矿基发光二极管的最大电致发光外量子效率为2.75%。
Metal halide perovskites are promising candidates for use in light emitting diodes (LEDs), due to their potential for color tunable and high luminescence efficiency. While recent advances in perovskite-based light emitting diodes have resulted in external quantum efficiencies exceeding 12.4% for the green emitters, and infrared emitters based on 3D/2D mixed dimensional perovskites have exceeded 20%, the external quantum efficiencies of the red and blue emitters still lag behind. A critical issue to date is creating highly emissive and stable perovskite emitters with the desirable emission band gap to achieve full color displays and white LEDs. Herein, we report the preparation and characterization of a highly luminescent and stable suspension of cubic-shaped methylammonium lead triiodide (CH3NH3PbI3) perovskite nanocrystals, where we synthesize the nanocrystals via a ligand-assisted reprecipitation technique, using an acetonitrile/methylamine compound solvent system to solvate the ions and toluene as the antisolvent to induce crystallization. Through tuning the ratio of the ligands, the ligand to toluene ratio, and the temperature of the toluene, we obtain a solution of CH3NH3PbI3 nanocrystals with a photoluminescence quantum yield exceeding 93% and tunable emission between 660 and 705 nm. We also achieved red emission at 635 nm by blending the nanocrystals with bromide salt and obtained perovskite-based light emitting diodes with maximum electroluminescent external quantum efficiency of 2.75%.