TY - GEN
T1 - Film Bulk Acoustic-wave Resonator (FBAR) based humidity sensor
AU - Qiu, Xiaotun
AU - Zhu, Jie
AU - Oiler, Jon
AU - Yu, Cunjiang
AU - Wang, Ziyu
AU - Yu, Hongyu
PY - 2010
Y1 - 2010
N2 - This paper described relative humidity (RH) sensing with ZnO based Film Bulk Acoustic-wave Resonator (FBAR). The resonant frequency of the FBAR decreased in a two-stage manner as the RH increased in the environment. For low RH (RH<50%), a frequency shift of 2.2 kHz per 1% RH change was observed. This effect was attributed to water molecules replacing the adsorbed oxygen on the ZnO surface, thus increasing the density of the film. While for high RH (RH>50%), a frequency shift of 8.5 kHz per 1% RH change was obtained, which was due to the mass loading effect of the water layers formed on the ZnO surface. Ultraviolet (UV) light was applied to monitor its effects on the humidity sensing performance of the FBAR. UV can enhance the sensitivity at low RH (response increased to 3.4 kHz per 1% RH change), while degrade the sensitivity at high RH (response decreased to 5.7 kHz per 1% RH change). This study has proven the feasibility of measuring relative humidity using ZnO film based FBAR.
AB - This paper described relative humidity (RH) sensing with ZnO based Film Bulk Acoustic-wave Resonator (FBAR). The resonant frequency of the FBAR decreased in a two-stage manner as the RH increased in the environment. For low RH (RH<50%), a frequency shift of 2.2 kHz per 1% RH change was observed. This effect was attributed to water molecules replacing the adsorbed oxygen on the ZnO surface, thus increasing the density of the film. While for high RH (RH>50%), a frequency shift of 8.5 kHz per 1% RH change was obtained, which was due to the mass loading effect of the water layers formed on the ZnO surface. Ultraviolet (UV) light was applied to monitor its effects on the humidity sensing performance of the FBAR. UV can enhance the sensitivity at low RH (response increased to 3.4 kHz per 1% RH change), while degrade the sensitivity at high RH (response decreased to 5.7 kHz per 1% RH change). This study has proven the feasibility of measuring relative humidity using ZnO film based FBAR.
UR - http://www.scopus.com/inward/record.url?scp=78649235101&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78649235101&partnerID=8YFLogxK
U2 - 10.1109/NEMS.2010.5592429
DO - 10.1109/NEMS.2010.5592429
M3 - Conference contribution
AN - SCOPUS:78649235101
SN - 9781424465439
T3 - 2010 IEEE 5th International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2010
SP - 445
EP - 449
BT - 2010 IEEE 5th International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2010
T2 - 5th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2010
Y2 - 20 January 2010 through 23 January 2010
ER -