Many illiterates believe that quantum mechanics is just a mathematical game with no practical value. Haha, let's find a ancestor for computer chips, please take a look at the demonstration:
Many illiterates believe that quantum mechanics is just a mathematical game with no practical value. Haha, let's find a ancestor for computer chips, please take a look at the demonstration:
Conductors, we can understand, insulators, we can also understand. For the first time, my friends have been confused by physics, and I'm afraid it's semiconductors. Therefore, I will repay this debt on behalf of all the physics teachers.
When atoms form a solid, there are many identical electrons mixed together, but quantum mechanics believes that two identical electrons cannot stay in the same orbit. Therefore, in order to prevent these electrons from fighting in the same orbit, many orbitals split into several orbitals. With so many orbitals squeezed together, they accidentally get closer and become wide large orbitals. This type of wide orbit formed by squeezing together many fine orbitals is called an energy band.
Some wide orbitals are crowded with electrons, making them unable to move. Some wide orbitals are very empty, allowing electrons to move freely. Electrons can move and appear to conduct electricity macroscopically. Conversely, if electrons cannot move, they cannot conduct electricity.
Alright, let's keep things simple and not mention the concepts of "price band, full band, forbidden band, and guide band". Prepare to focus on the circle!
Some full orbitals are too close to empty orbitals, and electrons can effortlessly move from the full orbit to the empty orbit, allowing them to move freely. This is a conductor. The conductivity principle of monovalent metals is slightly different.
But often there is a gap between two wide orbitals, and electrons cannot cross it alone, so they do not conduct electricity. But if the width of the gap is within 5 ev, adding extra energy to the electron can also cross the empty orbit and move freely across it, which is conductive. This type of solid with a gap width not exceeding 5 ev is sometimes conductive and sometimes not, so it is called a semiconductor.
If the gap exceeds 5 ev, then it basically has to be stopped. Under normal circumstances, electrons cannot cross, which is an insulator. Of course, if the energy is large enough, let alone the gap of 5 ev, even 50 ev can still run through, such as high-voltage electricity breaking through air.
At this point, the band theory developed by quantum mechanics has almost taken shape. The band theory systematically explains the essential differences between conductors, insulators, and semiconductors, which depend on the gap between the full and empty orbitals, and academically, on the bandgap width between the valence and conduction bands.
When atoms form a solid, there are many identical electrons mixed together, but quantum mechanics believes that two identical electrons cannot stay in the same orbit. Therefore, in order to prevent these electrons from fighting in the same orbit, many orbitals split into several orbitals. With so many orbitals squeezed together, they accidentally get closer and become wide large orbitals. This type of wide orbit formed by squeezing together many fine orbitals is called an energy band.
Some wide orbitals are crowded with electrons, making them unable to move. Some wide orbitals are very empty, allowing electrons to move freely. Electrons can move and appear to conduct electricity macroscopically. Conversely, if electrons cannot move, they cannot conduct electricity.
Alright, let's keep things simple and not mention the concepts of "price band, full band, forbidden band, and guide band". Prepare to focus on the circle!
Some full orbitals are too close to empty orbitals, and electrons can effortlessly move from the full orbit to the empty orbit, allowing them to move freely. This is a conductor. The conductivity principle of monovalent metals is slightly different.
But often there is a gap between two wide orbitals, and electrons cannot cross it alone, so they do not conduct electricity. But if the width of the gap is within 5 ev, adding extra energy to the electron can also cross the empty orbit and move freely across it, which is conductive. This type of solid with a gap width not exceeding 5 ev is sometimes conductive and sometimes not, so it is called a semiconductor.
If the gap exceeds 5 ev, then it basically has to be stopped. Under normal circumstances, electrons cannot cross, which is an insulator. Of course, if the energy is large enough, let alone the gap of 5 ev, even 50 ev can still run through, such as high-voltage electricity breaking through air.
At this point, the band theory developed by quantum mechanics has almost taken shape. The band theory systematically explains the essential differences between conductors, insulators, and semiconductors, which depend on the gap between the full and empty orbitals, and academically, on the bandgap width between the valence and conduction bands.