Draw the bands of MO energy levels and the electron population for: (a) A semiconductor (b) An electrical insulator Explain why a semiconductor has the higher electrical conductivity.

Video transcript

Hello. In this problem, we are asked to identify the semiconductor and electrical insulator from the given energy level diagrams. Were also asked to describe the reasons why semiconductors have greater electrical conductivity. So at the top then in the blue we have the conduction band and in the red we have the valence band. We see that be then the conduction band and the valence band overlap. This is our conductor. If we compare a two C, we see that C. Has a bigger gap and this bigger band gap then means that this is an insulator. We have a smaller band gap with a so this is our semiconductor. And so since we have a smaller band gap, it means then that we have electrons that will be able to bridge this gap. So we will have a partially filled conduction band and we will have a partially vacant valence band. The reason why semiconductors then have greater electrical conductivity is their ability to be able to bridge this gap and move from the valence band to the higher energy conduction band. So again, C. Is our insulator and a is our semiconductor. Thanks for watching. Hope this helped