摘要
In the present work the structural information of PbO-doped SnO2 thick film sensor has been investigated with X-ray diffractometer （XRD） and scanning electron microscope （SEM）. Initially, SnO2 powder was derived using sol-gel process and was subsequently doped with PbO and ground up to nanosized particles. A suitable gas sensor structure was fabricated on 1′′×1′′ alumina substrate using thick film technology. The necessary paste for screen printing was also developed. SEM results showed sol-gel derived powder gets more agglomerated in the thick film form. The sensitivity of the sensor has been investigated at different temperatures （150 ？C？350 ？C） upon exposure to methanol, propanol and acetone, yielding a maximum at 250 ？C for acetone with 1 wt% PbO-doping while at 350 ？C for propanol with 3 wt% PbO-doping of the sensor. The reduction of particle size to nanometers （validated through XRD） leads to a dramatic improvement in sensitivity of sensors for the chosen organic vapors. The results also correlate well with the microstructural properties of the material and the dopant.
In the present work the structural information of PbO-doped SnO2 thick film sensor has been investigated with X-ray diffractometer （XRD） and scanning electron microscope （SEM）. Initially, SnO2 powder was derived using sol-gel process and was subsequently doped with PbO and ground up to nanosized particles. A suitable gas sensor structure was fabricated on 1′′×1′′ alumina substrate using thick film technology. The necessary paste for screen printing was also developed. SEM results showed sol-gel derived powder gets more agglomerated in the thick film form. The sensitivity of the sensor has been investigated at different temperatures （150 ？C？350 ？C） upon exposure to methanol, propanol and acetone, yielding a maximum at 250 ？C for acetone with 1 wt% PbO-doping while at 350 ？C for propanol with 3 wt% PbO-doping of the sensor. The reduction of particle size to nanometers （validated through XRD） leads to a dramatic improvement in sensitivity of sensors for the chosen organic vapors. The results also correlate well with the microstructural properties of the material and the dopant.
