Chen Kaiwang, Du Qing, Cao Qiufen, Du Chao, Feng Shangwei, Pan Yutong, Liang Yue, Wang Lei, Chen Jiangshan, Ma Dongge
Institute of Polymer Optoelectronic Materials and Devices, Guangdong Basic Research Center of Excellence for Energy & Information Polymer Materials, State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence From Molecular Aggregates, South China University of Technology, Guangzhou, 510640, People's Republic of China.
Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China.
Nanomicro Lett. 2024 Nov 28;17(1):77. doi: 10.1007/s40820-024-01564-5.
Formamidinium lead bromide (FAPbBr) perovskite nanocrystals (NCs) are promising for display and lighting due to their ultra-pure green emission. However, the thermal quenching will exacerbate their performance degradation in practical applications, which is a common issue for halide perovskites. Here, we reported the heat-resistant FAPbBr NCs prepared by a ligand-engineered room-temperature synthesis strategy. An aromatic amine, specifically β-phenylethylamine (PEA) or 3-fluorophenylethylamine (3-F-PEA), was incoporated as the short-chain ligand to expedite the crystallization rate and control the size distribution of FAPbBr NCs. Employing this ligand engineering approach, we synthesized high quality FAPbBr NCs with uniform grain size and reduced long-chain alkyl ligands, resulting in substantially suppressed thermal quenching and enhanced carrier transportation in the perovskite NCs films. Most notably, more than 90% of the room temperature PL intensity in the 3-F-PEA modified FAPbBr NCs film was preserved at 380 K. Consequently, we fabricated ultra-pure green EL devices with a room temperature external quantum efficiency (EQE) as high as 21.9% at the luminance of above 1,000 cd m, and demonstrated less than 10% loss in EQE at 343 K. This study introduces a novel room temperature method to synthesize efficient FAPbBr NCs with exceptional thermal stability, paving the way for advanced optoelectronic device applications.
溴化甲脒铅（FAPbBr）钙钛矿纳米晶体（NCs）因其超纯绿色发射而在显示和照明领域颇具前景。然而，热猝灭会加剧其在实际应用中的性能退化，这是卤化物钙钛矿的一个常见问题。在此，我们报道了通过配体工程室温合成策略制备的耐热FAPbBr纳米晶体。引入一种芳香胺，具体为β-苯乙胺（PEA）或3-氟苯乙胺（3-F-PEA）作为短链配体，以加快结晶速率并控制FAPbBr纳米晶体的尺寸分布。采用这种配体工程方法，我们合成了具有均匀晶粒尺寸且减少了长链烷基配体的高质量FAPbBr纳米晶体，从而显著抑制了热猝灭并增强了钙钛矿纳米晶体薄膜中的载流子传输。最值得注意的是，3-F-PEA修饰的FAPbBr纳米晶体薄膜在380 K时保留了超过90%的室温PL强度。因此，我们制备了超纯绿色EL器件，在亮度高于1000 cd m时室温外量子效率（EQE）高达21.9%，并且在343 K时EQE损失小于10%。本研究引入了一种新颖的室温方法来合成具有卓越热稳定性的高效FAPbBr纳米晶体，为先进光电器件应用铺平了道路。
