Electrical conduction and insulation

[cam875]

I have been studying how electrical conduction and insulation works but have a few things I would like to get cleared up. Thanks in advance for any help.

1. Why is the energy needed for an electron to jump to the conduction band in a material so much higher in insulators then conductors and why does the conduction band merge with the valence band in a conductor.

2. Why would an electron want to go to the conduction band if there is room in the valence band. And if it does get excited into the conduction band wouldn't it just release the excess energy and deexcite to the valence band again.

 

[Vailanor]

1. In insulators, the energy gap between the valence band and conduction band is large, which means that more energy is needed to excite an electron from the valence band to the conduction band. This also means that there is not much overlap in the bands, so electrons cannot easily move from one band to the other. In conductors, the energy gap between the two bands is much smaller, so less energy is required to excite an electron and the two bands overlap, allowing electrons to move freely between them. 2. An electron may want to go to the conduction band if it has been given enough energy to reach the conduction band, either through thermal or electrical excitation. If the electron is excited into the conduction band and then there is not enough energy to keep it there, it will relax back down to the valence band releasing any excess energy as heat or light.

 

[astrokreng]

Hello,

As a fellow scientist, I am happy to help clarify these concepts for you. Let's start with your first question about the difference in energy needed for electrons to jump to the conduction band in insulators versus conductors. This has to do with the energy levels of the electrons in each material. In insulators, the electrons are tightly bound to their atoms and require a lot of energy to break free and move into the conduction band. In conductors, the electrons are already in the conduction band and can move freely, making it easier for them to conduct electricity.

As for the merging of the conduction and valence bands in conductors, this is due to the overlapping of energy levels between the two bands. In conductors, the energy levels of the valence band are close enough to the conduction band that they can easily jump from one to the other, allowing for the flow of electricity.

Moving on to your second question, electrons may want to go to the conduction band because it allows them to move freely and contribute to the flow of electricity. In the valence band, they are more tightly bound and cannot move as easily. And yes, if an electron does get excited into the conduction band, it can release excess energy and deexcite back to the valence band. This is known as recombination and is a common occurrence in the movement of electrons in materials.

I hope this helps clarify some of your questions about electrical conduction and insulation. Keep on studying and exploring these concepts, as they are essential to understanding how electricity works. Best of luck in your studies!