Say If I have an electronic device like a resistor or MOSFET or OFET, what is the suitable range of current that can be used to sense a particular gas?
If you mean semiconductor sensors to determine the concentration of some gases, the current is determined by the current-voltage characteristics of the semiconductor and the characteristics of the sensitive layer material. Typically, this range from picoampere to microampere.
My experience tells that current should not be in pA and also should not be in mA. Basically, the sensing material should not have very high resistivity (pA current or nA current) and also it should not be very conducting. Both will affect your gas senisng performance. In low current range, you may observe very high background noise (can not not see ppb or ppt level detection if mangitude is not significantly high). In case of high current, you may see that gas has not signifuicant change during exposure. High resistive material can sense gases but require very high temperature (power consumption will be more). On the other hand, low resistive material will suffer with resonable gas resolution detection. Here is long story in short,.....It may or may not help you :)
Thanks C. S. Prajapati (Shekhar) for sharing your valuable experience. We also think that uA range is most suitable range for a FET device for gas sensing.
completely depends on sensor, fab methos, process technologies, mostly PPM
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