Fast response methane sensor using nanocrystalline zinc oxide thin films derived by sol–gel method

Zinc Oxide Nanostructure Thick Films as H<sub>2</sub>S Gas Sensors at Room Temperature

“…It has been proved that ZnO is a good gas sensitive material for detection of both reducing and oxidizing gases [8][9][10][11][12][13][14][15][16]. Various gases have been tested for ZnO nanostructure sensor studied including ethanol, acetone, NO 2 , NH 3 , H 2 and CO 2 and hydrogen [17][18][19][20][21][22].…”

Nanocrystalline Metal Oxides for Methane Sensors: Role of Noble Metals

“…• C is reported [118][119][120] depending upon whether the ZnO sensing film was grown electrochemically or by a sol-gel method, respectively. But these relatively high temperatures for detection of methane are still not suitable for applications in the coalmines.…”

“…There are very few reports on Zinc oxide-based methane gas sensors with high response and faster response time and recovery time. So far the reported sensor structures on the oxidebased semiconductors and operating in the resistive mode at high temperatures showed longer response and recovery time [118][119][120][121][122][123][124][125][126][127]. Bhattacharyya et al [120] studied the sol-gel grown ZnObased gas sensors in the resistive mode.…”

“…Recently Bhattacharyya et al [125] reported a ZnObased resistive sensors with Au and Pd-Ag contact. The ZnO thin film was deposited by Sol-gel method.…”

Nanocrystalline ZnO based MEMS Gas Sensors with CMOS ASIC for Mining Applications

“…MEMS technology has been presently employed in sensor technology in miniaturization of the devices, low power consumption, faster response and greater sensitivity [8]. But these MEMS based sensors still are reported to operate at high temperature(≥ 300 0 C).To achieve the lower operating temperature at a relatively low cost, a modified structure of sensor has been proposed employing nanocrystalline ZnO as the sensing material and nickel as microheater element instead of commonly used platinum or polysilicon and using sol-gel process for depositing nc zinc oxide [9] and silicon dioxide [10]. Also for hazardous environments like underground coalmines where continuous monitoring of hazardous gas concentration is required it is extremely desirable that the entire signal-processing unit capable of amplifying low signal level output from the sensor as well as transmitting the modified signal to remote control station, should be integrated along with the sensor platform [11,12].There are some reports on the development of integrated gas sensor systems with log-invertor circuits for linearising the output voltage [13].…”