Highly sensitive strain sensors based on piezotronic tunneling junction

• Published in: Nature communications Vol. 13; no. 1; p. 778
• Main Authors: Yu, Qiuhong, Ge, Rui, Wen, Juan, Du, Tao, Zhai, Junyi, Liu, Shuhai, Wang, Longfei, Qin, Yong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09.02.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/925/927/356; 639/925/927/511; Artificial intelligence; Biomedical engineering; Hafnium oxide; Humanities and Social Sciences; Internet of Things; multidisciplinary; Nanoelectromechanical systems; Nanotechnology; Nanowires; Piezoelectricity; Science; Science (multidisciplinary); Sensors; Transport processes; Zinc oxide
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-28443-0

Piezotronics with capacity of constructing adaptive and seamless interactions between electronics/machines and human/ambient are of value in Internet of Things, artificial intelligence and biomedical engineering. Here, we report a kind of highly sensitive strain sensor based on piezotronic tunneling junction (Ag/HfO 2 /n-ZnO), which utilizes the strain-induced piezoelectric potential to control the tunneling barrier height and width in parallel, and hence to synergistically modulate the electrical transport process. The piezotronic tunneling strain sensor has a high on/off ratio of 478.4 and high gauge factor of 4.8 × 10 5 at the strain of 0.10%, which is more than 17.8 times larger than that of a conventional Schottky-barrier based strain sensor in control group as well as some existing ZnO nanowire or nanobelt based sensors. This work provides in-depth understanding for the basic mechanism of piezotronic modulation on tunneling junction, and realizes the highly sensitive strain sensor of piezotronic tunneling junction on device scale, which has great potential in advanced micro/nano-electromechanical devices and systems. Strain-induced piezoelectric polarization can be used to modulate the interface electrical transport. Here, the authors achieved a piezotronic tunneling strain sensor at device scale with optimized performance based on the structure of Ag/HfO2/n-ZnO.