Liu Yang, Li Fushan, Qiu Lichun, Yang Kaiyu, Li Qianqian, Zheng Xin, Hu Hailong, Guo Tailiang, Wu Chaoxing, Kim Tae Whan
Institute of Optoelectronic Technology , Fuzhou University , Fuzhou 350002 , People's Republic of China.
Department of Electronic Engineering , Hanyang University , Seoul 133-791 , Republic of Korea.
ACS Nano. 2019 Feb 26;13(2):2042-2049. doi: 10.1021/acsnano.8b08582. Epub 2019 Feb 12.
Perovskite materials have exhibited promising potential for universal applications including backlighting, color conversion, and anticounterfeiting labels fabricated using solution processes. However, owing to the tendency of those materials to have uncontrollable morphologies and to form large crystals, they cannot be utilized in discontinuous microminiaturization, which is crucial for practical optoelectronic applications. In this research, combining the effects of adding polyvinylpyrrolidone (PVP), precisely controlling the inkjet printing technique, and using a postprocessing procedure, we were able to fabricate in situ crystallized perovskite-PVP nanocomposite microarrays with perfect morphologies. The viscosity of the perovskite precursor increased with the addition of PVP, eliminating the outward capillary flow that induces the coffee-ring effect. In addition, because of the presence of metallic bonds with the C═O groups in PVP and the spatial confinement of such a polymer, we were able to fabricate regulated CsPbBr nanocrystals capped with PVP and with a uniform size distribution. The as-printed patterns showed excellent homogeneity on a macroscale and high reproducibility on a microscale; furthermore, those patterns were invisible in the ambient environment, compatible with flexible substrates, and cost-efficient to produce, indicating that this technique holds promising potential for applications such as anticounterfeiting labels.
钙钛矿材料在包括背光、颜色转换以及使用溶液工艺制造的防伪标签等通用应用中展现出了广阔的应用潜力。然而，由于这些材料具有形态难以控制且容易形成大晶体的倾向，它们无法用于对于实际光电应用至关重要的不连续微缩化工艺。在本研究中，通过结合添加聚乙烯吡咯烷酮（PVP）的效果、精确控制喷墨打印技术以及采用后处理程序，我们成功制备出了具有完美形态的原位结晶钙钛矿 - PVP纳米复合微阵列。随着PVP的添加，钙钛矿前驱体的粘度增加，消除了导致咖啡环效应的向外毛细管流动。此外，由于PVP中C═O基团形成的金属键以及这种聚合物的空间限制作用，我们能够制备出表面被PVP包覆且尺寸分布均匀的规整CsPbBr纳米晶体。打印出的图案在宏观尺度上显示出优异的均匀性，在微观尺度上具有高重现性；此外，这些图案在环境中不可见，与柔性基板兼容且生产成本低廉，这表明该技术在防伪标签等应用方面具有广阔的应用潜力。
