TY - JOUR
T1 - Ultra-thin Glass Based Flexible, Transparent and Ultra-sensitive Surface Acoustic Wave Humidity Sensor with ZnO Nanowires and Graphene Quantum Dots
AU - Wu, Jianhui
AU - Yin, changshuai
AU - Zhou, Jian
AU - Li, Honglang
AU - Liu, Yi
AU - Shen, Yiping
AU - Garner, Sean
AU - Fu, Richard
AU - Duan, Huigao
PY - 2020/9/2
Y1 - 2020/9/2
N2 - Flexible electronic devices are normally based on organic polymer substrate. In this work, ultra-thin glass based flexi-ble, transparent and ultra-sensitive ZnO/glass surface acous-tic wave (SAW) humidity sensor is developed using a compo-site sensing layer of ZnO nanowires (NWs) and graphene quantum dots (GQDs). It shows much larger effective elec-tromechanical coupling coefficients and signal amplitudes, compared with those of flexible polymer based SAW devices reported in literature. Attributed to large specific surface are-as of ZnO NWs, large numbers of hydrophilic functional groups of GQDs, as well as the formation of p-n heterojunc-tions between GQDs and ZnO NWs, the developed ZnO/glass flexible SAW sensor shows an ultra-high humidity sensitivity of 40.16 kHz/%RH, along with its excellent stability and re-peatability. This flexible and transparent SAW sensor has demonstrated insignificant deterioration of humidity sensing performance, when it is bent on a curved surface with a bend-ing angle of 30, revealing its potential applications for sens-ing on curved and complex surfaces. The humidity sensing and human breathing detection have further been demon-strated for wearable electronic applications using ultra-thin glass based devices with completely inorganic materials.
AB - Flexible electronic devices are normally based on organic polymer substrate. In this work, ultra-thin glass based flexi-ble, transparent and ultra-sensitive ZnO/glass surface acous-tic wave (SAW) humidity sensor is developed using a compo-site sensing layer of ZnO nanowires (NWs) and graphene quantum dots (GQDs). It shows much larger effective elec-tromechanical coupling coefficients and signal amplitudes, compared with those of flexible polymer based SAW devices reported in literature. Attributed to large specific surface are-as of ZnO NWs, large numbers of hydrophilic functional groups of GQDs, as well as the formation of p-n heterojunc-tions between GQDs and ZnO NWs, the developed ZnO/glass flexible SAW sensor shows an ultra-high humidity sensitivity of 40.16 kHz/%RH, along with its excellent stability and re-peatability. This flexible and transparent SAW sensor has demonstrated insignificant deterioration of humidity sensing performance, when it is bent on a curved surface with a bend-ing angle of 30, revealing its potential applications for sens-ing on curved and complex surfaces. The humidity sensing and human breathing detection have further been demon-strated for wearable electronic applications using ultra-thin glass based devices with completely inorganic materials.
U2 - 10.1021/acsami.0c09962
DO - 10.1021/acsami.0c09962
M3 - Article
SN - 1944-8244
VL - 12
SP - 39817
EP - 39825
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 35
ER -