In the company you work as an engineer, you are assigned to determine the electrical conductivity of a new intrinsic semi-conductive material at temperatures of 20 and 100 °C and the band gap (Eg). So you cut out this material in the form of a rectangular prism with a length of 30 cm, a width of 1 cm and a thickness of 2 cm and apply a potential difference of 1 V size by placing the electrodes on the faces shown. In this case, you have observed that the current flows at 0.8A at 20 °C and 12A at 100 °C. According to this information a) calculate the electrical conductivity of the material at 20 °C and 100 °C and b) the band gap of this material.

I found the electrical conductivity of the material. How can I find the band gap of this material?

1 answer

I am not certain what you did. But for intrinistic semi-conductors, if you can know :(or calculate) the charge carrier density, it is related

n=constant (e-(bandgap/2kT)
so of you plot ln(n) vs 1/T, the slope is -Egap/2k

you know k, so Egap is then known.