Zhang Pengxiang, Fu Yushui, Zhang Xin, Zhang Xihua, Li Bao-Wen, Nan Ce-Wen
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, China.
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China.
Sci Bull (Beijing). 2022 Dec 31;67(24):2541-2549. doi: 10.1016/j.scib.2022.12.003. Epub 2022 Dec 5.
Chemically exfoliated nanosheets have exhibited great potential for applications in various electronic devices. Solution-based processing strategies such as inkjet printing provide a low-cost, environmentally friendly, and scalable route for the fabrication of flexible devices based on functional inks of two-dimensional nanosheets. In this study, chemically exfoliated high-k perovskite nanosheets (i.e., CaNbO and CaNaNbO) are well dispersed in appropriate solvents to prepare printable inks, and then, a series of microcapacitors with Ag and graphene electrodes are printed. The resulting microcapacitors, Ag/CaNbO/Ag, graphene/CaNbO/graphene, and graphene/CaNaNbO/graphene, demonstrate high capacitance densities of 20, 80, and 150 nF/cm and high dielectric constants of 26, 110, and 200, respectively. Such dielectric enhancement in the microcapacitors with graphene electrodes is possibly attributed to the dielectric/graphene interface. In addition, these microcapacitors also exhibit good insulating performance with a moderate electrical breakdown strength of approximately 1 MV/cm, excellent flexibility, and thermal stability up to 200 ℃. This work demonstrates the potential of high-k perovskite nanosheets for additive manufacturing of flexible high-performance dielectric capacitors.
化学剥离的纳米片在各种电子器件应用中展现出了巨大潜力。基于溶液的加工策略，如喷墨打印，为基于二维纳米片功能墨水制造柔性器件提供了一种低成本、环境友好且可扩展的途径。在本研究中，化学剥离的高介电常数钙钛矿纳米片（即CaNbO和CaNaNbO）在适当溶剂中良好分散以制备可打印墨水，然后打印一系列具有银和石墨烯电极的微电容器。所得微电容器Ag/CaNbO/Ag、石墨烯/CaNbO/石墨烯和石墨烯/CaNaNbO/石墨烯分别展示出20、80和150 nF/cm的高电容密度以及26、110和200的高介电常数。具有石墨烯电极的微电容器中的这种介电增强可能归因于介电体/石墨烯界面。此外，这些微电容器还表现出良好的绝缘性能，具有约1 MV/cm的适度电击穿强度、出色的柔韧性以及高达200℃的热稳定性。这项工作证明了高介电常数钙钛矿纳米片在柔性高性能介电电容器增材制造方面的潜力。
