How does electrical conductivity of a semiconductor change with temperature? why?
Answers
Explanation:
well, conductivity of semi conductor increase on increasing temperature.
lets take pn junction diode( forward bias) it have one side of +ve, and other -ve.
when we apply small current + ve(holes) pushed by +ve side of battery.
and - ve( electron) pushed by - ve side of battery , so there is barrier potential between them starts weaken then, current start rising if too much current is passed the then current will grow exponentially.and semiconductor heats gives mobility to electron , which is fixed in solid state of semiconductor, but now it's free
that's why conductivity increased .
This is condition given for forward biased pn junction.
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Answer:
The electrical conductivity of semiconductors increases with increasing temperature because, with increase in temperature, number of electrons from the valence bond can jump to the conduction band in semiconductors.
When the temperature in increased the forbidden gap between the two bands becomes very less and the electrons move from the valence band to the conduction band. Thus some electrons become free to move within the structure. This increases the conductivity of the material.