标题：Strategy for improving Ag wetting on oxides: Coalescence dynamics versus nucleation density
作者：Zhao, Guoqing ;Jeong, Eunwook ;Choi, Eun-Ae ;Yu, Seung Min ;Bae, Jong-Seong ;Lee, Sang-Geul ;Han, Seung Zeon ;Lee, Gun-Hwan ;Yun, Jungheum
作者机构：[Zhao, Guoqing ;Jeong, Eunwook ;Lee, Gun-Hwan ;Yun, Jungheum ] Surface Technology Division, Korea Institute of Materials Science, Changwon; Gyeongnam; 更多
通讯作者地址：[Choi, E.-A] Materials Processing Innovation Research Division, Korea Institute of Materials ScienceSouth Korea;
来源：Applied Surface Science
关键词：DFT simulation; Nanoparticle coalescence; Nucleation density; Silver; Transparent electrode; Wetting improvement
摘要：Wetting of noble metals on oxide structures becomes problematic when attempting to grow two-dimensional, atomically smooth and continuous thin film structures because of a strong tendency for three-dimensional growth. This study redefines the crucial factor that controls the wetting of vacuum deposited Ag on SiO2 substrates and refutes the currently accepted assertion that increasing the nucleation density of Ag is responsible for promoting wetting. Ultrahigh-resolution electron microscopy, supported by X-ray spectroscopic techniques, was used to observe how fast Ag nanoparticles evolve to a continuous film by manipulating the contribution of the crucial factor on Ag wetting, and the results were numerically interpreted using first-principles density functional theory calculations to reveal the relevant dynamics. The experimental and numerical results confirmed that the earliest transition of the coalescence dynamics of Ag nanoparticles from full to partial coalescence is the dominating factor in improving Ag wetting. Surprisingly, Ag wetting is independent of the initial nucleation density of Ag nanoparticles. Favorable partial coalescence with more irregularities in the shapes was readily attainable by artificially reducing the thermodynamic surface and interfacial free energies of the evolving Ag nanoparticles through the addition of a small concentration of Al or O as a wetting agent. © 2020 Elsevier B.V.