Professor, Shenzhen Institutes of Advanced Technology
Hierarchical self-assembled copper 3D microstructures with excellent antioxidation and sinterablity toward flexible electronics applications
Xinyan Hu (1) , Gang Li (2) , Pengli Zhu (2)* , Tao Zhao (2) , Rong Sun (2) , Chingping Wong (2) (1) College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China (2) Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China,
Due to its low price and high electrical conductivity, Cu based conductive ink is expected to be a promising alternative to Ag conductive ink for flexible printed electronic interconnections applications. 1 However, strong oxidation and poor sinterability have significantly limited their wide applications. There is significant work in literature to solve these problems, usually involving the inorganic or organic functionalization of individual nanoparticle. 2 However, very little attention has been focused on understanding how the NP structure affects these properties. In our work, we have successfully synthesized a novel copper 3D hierarchical microstructure based on self-assemble strategy. SEM images reveal that the copper particles with an average diameter of 500 nm, as building blocks, tend to self-assemble into three-dimensional (3D) microspheres approximately 4μm in diameter. The as-prepared Cu hierarchical microstructures exhibited long-term stability against oxidation even after storage for 3 months due to self-passivation effect. Due to the weak interaction force between the building blocks, the copper microstructure can evolve into sheet-like structures under ball-milling treatment, which endows it an excellent sinterability. The Cu patterns showed a minimum resistivity of 10 −7 Ω·m when sintered in nitrogen at 350°C for 30 min. The design of hierarchical copper structure provides a new way for preparing copper with strong antioxidation and excellent sinterability, which will promote the wide applications of copper ink in flexible electronics.
Figure 1 (a)SEM, (b) XRD of the obtained Cu microstructure and (c) electrical resistance of Cu pattern
sintered at various temperature.
 Abhinav K, V.; Rao R, V. K.; Karthik, P. S.; Singh, S. P., RSC Advances 2015, 5 (79).
 Liu, X.; Du, J.; Shao, Y.; Zhao, S. F.; Yao, K. F., Sci Rep 2017, 7 (1), 10249.
Pengli Zhu received the Ph.D. degree from the Chinese Academy of Sciences, Beijing, China, in 2010. Now she is a Professor in Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences (SIAT-CAS). Member of the Youth Innovation Promotion Association of CAS, “Guangdong TeZhi plan” Youth Talent of Science and Technology and also the Shenzhen peacock plan C class talent. She has been in charge of two NSFC projects, three Shenzhen projects and also as a core members to take part in the National 02 major project, two 973 projects and other team program. Until now, the applicant has published more than 120 academic papers, in which, 60 papers are SCI papers. The applicant has applied for more than 80 patents, of which 20 has been issued. Her research interests include the nanomaterials, nanocomposites and their corresponding applications in the flexible electronics, pressure sensors and electronic packaging.
The Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Science (CAS) comprise 8 institutes and numerous other labs and facilities. SIAT was jointly established by CAS, the Shenzhen municipal government and the Chinese University of Hong Kong in February 2006. SIAT aims to enhance the innovative capacity of the equipment manufacturing and service industries in the Guangdong-Hong Kong region, promote the development of emerging industries possessing their own proprietary intellectual property, and become a world-class industrial research institute.