3D printing of inorganic nanomaterials by photochemically bonding colloidal nanocrystals
Fu Li, Shao-Feng Liu, Wangyu Liu, Zheng‐Wei Hou, Jiaxi Jiang, Zhong Fu, Song Wang, Yilong Si, Shaoyong Lu, Hongwei Zhou, Dan Liu, Xiaoli Tian, Hengwei Qiu, Yuchen Yang, Zhengcao Li, Xiaoyan Li, Linhan Lin, Hong‐Bo Sun, Hao Zhang, Jinghong Li
Abstract
3D printing of inorganic materials with nanoscale resolution offers a different materials processing pathway to explore devices with emergent functionalities. However, existing technologies typically involve photocurable resins that reduce material purity and degrade properties. We develop a general strategy for laser direct printing of inorganic nanomaterials, as exemplified by more than 10 semiconductors, metal oxides, metals, and their mixtures. Colloidal nanocrystals are used as building blocks and photochemically bonded through their native ligands. Without resins, this bonding process produces arbitrary three-dimensional (3D) structures with a large inorganic mass fraction (~90%) and high mechanical strength. The printed materials preserve the intrinsic properties of constituent nanocrystals and create structure-dictated functionalities, such as the broadband chiroptical responses with an anisotropic factor of ~0.24 for semiconducting cadmium chalcogenide nanohelical arrays.