Detection of nitrogen dioxide using mixed tungsten oxide-based thick film semiconductor sensor.
The thick film semiconductor sensor for NO(2) gas detection was fabricated by screen-printing method using a mixed WO(3)-based as sensing material. The sensing characteristics, such as response time, response linearity, sensitivity, working range, cross sensitivity, and long-term stability were further studied by using a WO(3)-based mixed with different metal oxides (SnO(2), TiO(2) and In(2)O(3)) and doped with noble metals (Au, Pd and Pt) as sensing materials was observed. The highest sensitivity for low concentrations (<16 mg l(-1)) was observed using WO(3)-based mixed with In(2)O(3) or TiO(2). The NO(2) gas sensor showing the fastest response and recovery time (both within 2 min), good linearity (Y=0.606X+0.788 R(2)=0.991) for gas concentrations from 3 to 310 mg l(-1), low resistance (3 MOmega), high sensitivity, undesirable cross sensitivity effect and good long-term stability (at least 120 days) using WO(3)-SnO(2)-Au as sensing material.
Su
P-G
PG
Tzu-Hui Institute of Technology, No. 367 San-Min Road, Nan-Zhou Village, Ping-Tung County 926, Taiwan. pigueysu@mail1.tzuhui.edu.tw
Ren-Jang
Wu
W
Fang-Pei
Nieh
N