Spin coated Tin dioxide nanoparticle film for ppb level concentration of   Hydrogen and Acetone vapor gas senor

Salim F. Bamsaoud^{* 1, 2}, R.N.Karekar³ and R. C. Aiyer²

1. Department of Physics, Science Faculty, Hadhramout University, Mukalla, Yemen.

2. Center for Sensor Studies, Department of Physics, University of Pune, Pune 411002.

3. RCMF Transducer Lab, Department of Physics, University of Pune, Pune-411 007.

E-mail: salim88@physics.unipune.ernet.in  

Tin dioxide films are formed on soda - lime glass substrate using spin coating technique. The films are fired at an optimal firing temperature of 550^oC. The films are showing a highest sensitivity factor (Ra/Rg ~ 18 at 800 ppm of H₂) at operating temperature of 275^oC + (4%). XRD shows that the 550^oC films are not only having small grain size (8+ 0.6 nm) but they are also having a highest percentage presence of Tetragonal phase. The sensors are tested for H₂ concentrations of 1000, 100,50ppb at operating temperature of 275^oCand the sensors show a good sensitivity of ~ 0.2/1000 ppb, 0.05/100 ppb and 0.03/50ppb.Further , the sensitivity curve of H₂ sensor at operating temperature of 275^oC concentrations 1000-10000 ppb is checked in presence of different percentage of relative humidity (RH% 20-100%) and different ppm (150-900) concentrations of different   gases (CO₂, CO and LPG).All have given good selectivity for H₂ ,because the H₂ sensitivity in presence of all these gases remain nearly same(0.2/1000ppb).

When the sensor showed a zero SF of 1000ppb H₂ at operating temperature of 200^oC, but at this operating temperature the Acetone vapor is seen to give the sensitivity factor of ~1.2/20ppb of Acetone. Thus this nanoparticle film sensor could be used as H₂ sensor at operating temperature of 275^oC (from 50ppb to 800ppm in air ambient) with good selectivity against CO₂, CO, LPG, and humidity, as well as an Acetone sensor at operating temperature of 200^oC with good selectivity against H₂. To the best of our knowledge such a low level H₂and Acetone senor are not reported.  

Keywords: Nano size Tin dioxide, Spin coated film, selectivity, Hydrogen, Acetone, sensor.

*Corresponding author contact:

Sensor Lab., Department of Physics, University of Pune, Pune 411007, India

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