Timeline for In an intrinsic semiconductor, why don't electrons go out from both valence and conduction bands?
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| when toggle format | what | by | license | comment | |
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| Mar 2, 2020 at 2:30 | vote | accept | across | ||
| Feb 28, 2020 at 19:24 | comment | added | Cristobol Polychronopolis | It works the same way, but the current in the valence band is much higher than the current in the conduction band. You don't need equal quantities of conduction electrons and valence holes...that's why doping works, it gives you an excess of one or the other. | |
| Feb 28, 2020 at 18:46 | comment | added | Sredni Vashtar | @beccabecca if it is p-doped you placed traps near the top of the valence band. That will make electron from the valence band jump into the traps just with a bit of thermal energy, thus freeing holes in the valence band. These holes will flow in the direction of the E field, while the bulk of the electrons in valence band can be thought of flowing the opposite way. There are nice pictures of the 'liquid in a pipe' analogy on Mueller and Kamins book. I could not find the picture online, tho. | |
| Feb 28, 2020 at 17:31 | comment | added | across | Thank you @Cristbol In pure crystal, I see that the conduction band free electrons move toward the positive side of battery and the valence band free holes move toward the negative side of the battery. But in a p-type doped crystal, battery has to pull the electrons from valence band because the number of conduction band free electrons is almost 0. How can the battery pull the valence band electrons here if they are bound tightly to the atoms as you said? | |
| Feb 28, 2020 at 17:24 | history | answered | Cristobol Polychronopolis | CC BY-SA 4.0 |