Directional Assembly of ZnO Nanowires via Three-Dimensional Laser Direct Writing

• Published in: Nano letters 2020-07, Vol.20 (7), p.5159-5166
• Main Authors: Long, Jing, Xiong, Wei, Wei, Chengyiran, Lu, Chengchangfeng, Wang, Ruiqing, Deng, Chunsan, Liu, Huan, Fan, Xuhao, Jiao, Binzhang, Gao, Shan, Deng, Leimin
• Format: Article
• Language: English
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.0c01378

The precise placement of semiconductor nanowires (NWs) into two- or three-dimensional (2D/3D) micro-/nanoarchitectures is a key for the construction of integrated functional devices. However, long-pending challenges still exist in high-resolution 3D assembly of semiconductor NWs. Here, we have achieved directional assembly of zinc oxide (ZnO) NWs into nearly arbitrary 3D architectures with high spatial resolution using two-photon polymerization. The NWs can regularly align in any desired direction along the laser scanning pathway. Through theoretical calculation and control experiments, we unveiled the laser-induced assembly mechanism and found that the nonoptical forces are the dominant factor leading to the directional assembly of ZnO NWs. A ZnO-NW-based polarization-resolved UV photodetector of excellent photoresponsivity was fabricated to demonstrate the potential application of the assembled ZnO NWs. This work is expected to promote the research on NW-based integrated devices such as photonic integrated circuits, sensors, and metamaterial with unprecedented controllability of the NW’s placement in three dimensions.