Ultraviolet sensor with fast response characteristics based on an AgNW/ZnO bi-layer

• Published in: Sensors and actuators. A. Physical. Vol. 311; p. 112044
• Main Authors: Jeon, Mun-Bae, Kwak, Yeon Hwa, Ju, Byeong-Kwon, Kim, Kunnyun
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.08.2020; Elsevier BV
• Subjects: Acoustoelectric effect; Bilayers; Frequency response; Lithium niobates; Nanomaterials; Piezoelectricity; Response characteristics; Sensors; Silver nanowire; Substrates; Surface acoustic wave; Surface acoustic wave devices; Surface acoustic waves; Ultraviolet; Ultraviolet radiation; Zinc oxide; Zinc oxides; Acoustoelectric effect; Zinc oxide; Silver nanowire; Surface acoustic wave; Ultraviolet; Response characteristics
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2020.112044

[Display omitted] •Ultraviolet sensor using AgNW/ZnO bi-layer based surface acoustic wave was demonstrated.•Fabricated AgNW/ZnO-based SAW sensor showed fast response characteristics.•This sensor detects ultraviolet in the range of UVA, UVB and UVC.•The proposed sensor provides the fastest response characteristics among the SAW sensors with ZnO. We demonstrate an ultraviolet (UV) sensor with fast response characteristics based on an AgNW/ZnO bi-layer. This UV sensor is a surface acoustic wave (SAW)-based sensor fabricated using a 128°YX black lithium niobate substrate, which is a piezoelectric in nature. This sensor, which is a two-port SAW resonator, was manufactured by fabricating interdigitated electrodes with a wavelength of 16.4 μm and depositing UV sensing layers such as ZnO, Sn/ZnO, and AgNW/ZnO. Among these sensing layers, the frequency response characteristics were found to be improved in the bi-layer structure. In addition, the AgNW/ZnO-based sensor showed a significant improvement in response and recovery times. These results contributed to rapid oxygen adsorption on the ZnO surface due to the large oxygen contact area that can attributed to the AgNW’s 3D mesh structure and the compensation of the internal electron trap center due to the contact of the metal-semiconductor. The proposed sensor with the metal-semiconductor bi-layer structure based on AgNW nanomaterials showed the fastest response characteristics compared to previous SAW UV sensors.