Assessing three different ranges of amounts of silver nanoparticle dopants on the ethanol sensing properties of zinc oxide

作者：Mohammadrezaei Ameneh^*; Afzalzadeh Reza; Hosseini Golgoo Seyed Mohsen

来源：Measurement Science and Technology, 2012, 23(3): 035106.

DOI：10.1088/0957-0233/23/3/035106

• resistive gas sensor
• zinc oxide
• Ag nanoparticles
• solubility
• sensor response
• response and recovery time

The effects of silver nanoparticle (SNP) dopants on the ethanol sensing properties of zinc oxide (ZnO) bulk sensors were investigated. ZnO powder was mixed with various weight percentages of SNPs in the range of 0-1.8 wt% and then all samples were sintered at 860 degrees C. X-ray diffractometry was used to determine the crystal structure of the doped samples. Scanning electron microscopy was used to characterize the structure of the specimens. The electrical and gas-sensing properties of the specimens were assessed at different temperatures. Three different ranges of additive amount were distinguished based on the sensing behavior of the samples as a result of the solubility of SNPs in ZnO samples. In the first range, a tiny amount of the SNPs (similar to 0.025 wt%) can be dissolved in the ZnO lattice, so the resistance and response of the bulk ZnO sensors are decreased. In the second range (0.025% < wt% < 0.7%), those parameters are increased, revealing that Ag cannot be dissolved in ZnO at higher concentration. Best recovery time is achieved in this range at 0.7 wt% of SNP dopants. In the third range (wt% > 0.7%), the resistance is observed to increase and the response to decrease with a high accumulation of Ag clusters on the grain surfaces. Moreover, the working temperature is reduced by increasing the amount of SNPs.

• 出版日期2012-3