The development of high-density integrated micro-nano devices continues to inspire people to explore more technical methods that can break through the welding size limitations. nanojunction technology, as one of the key technologies to promote the integration and packaging level of nano-functional structured devices, the method of connection and interconnection mechanism has become a hotspot for research. ag nanowires, as an ideal material for bonding of flexible opto-electronic devices and micro-nanochips, exploring the preparation of nanointerconnection joints with excellent mechanical, electrical and optical properties has become a key area of research. As an ideal material for bonding flexible optoelectronic devices and micro- and nano-chips, it is crucial to explore the preparation of nano-interconnection joints with excellent mechanical, electrical and optical properties, especially for some flexible devices. However, the realization of nanoscale welding and local energy control has also become an important challenge, especially to realize the precise and controllable welding process of single Ag nanowires, which puts forward higher requirements on welding conditions and energy control.
To address the above problems, the teams of Prof. Xuesong Mei and Jianlei Cui from School of Mechanical Engineering, Xi'an Jiaotong University and Prof. Yang Lu from University of Hong Kong have successfully obtained Ag nanowire interconnect joints with high electrical and mechanical properties comparable to those of the base material based on the nano-focusing and localized plasma enhancement of Ag nanowires under laser irradiation, and the combination of in-situ Ag nanowire soldering and nano-mechanical experiments. effectively solve the problems of nanoscale heat source control and welding efficiency.
Strong localized plasma enhancement at the laser-induced Ag nanowire joint gap, especially in the presence of nanoparticle clusters or sharp concave structures, leads to localized energy concentration at the tip. The local plasma resonance characterization in the Ag nanowire joint nanogap is investigated by cathodoluminescence technique and combined with theoretical simulations to systematically analyze the local multi-physical field coupling regulation mechanism of Ag nanowire joints induced by different laser parameters, so as to realize the control of nanoscale heat source in the nanowire welding gap. In addition, by further combining the in-situ welded interface characteristics and theoretical simulations of Ag nanowires under different laser welding energies, the interface atomic behavior characteristics and evolution processes during their welding and stretching processes can be further obtained.
Recently, the relevant research results were published in the international authoritative journal Advanced Materials. Xiaoying Ren, a PhD student at the School of Mechanical Engineering, Xi'an Jiaotong University (XJTU), is the first author of the paper, while Prof. Xuesong Mei and Jianlei Cui of XJTU, and Prof. Yang Lu of the University of Hong Kong (HKU), with Xi'an Jiaotong University (XJTU) as the first organization, are the co-corresponding authors.
This research work was supported by the National Natural Science Foundation of China and the Key Research and Development Program of Shaanxi Province.
