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In a homojunction the barrier potential depends on the difference in Fermi levels been the n and p sides. If different materials are used (heterojunction) then there is an additional potential from intrinsic difference in electron affinity.


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There is a very nice demonstration that you can treat holes as positively charged carriers in the Hall effect. As you may know, to observe the Hall effect we place a semiconductor in a magnetic field and pass a current through it. We observe a polarization (voltage) at right angles to both the current and the magnetic field as a consequence of the Lorentz ...


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Holes are technically just vacancies, but when an electron jumps into this vacancy, one more hole is created, but this constant filling up of a hole and creation of a hole appears as if the hole is moving, that is it appears as if there are these +ve carriers which are moving in the direction of the current (opposite to that of the direction of electron) ...


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Yes, since more electrons are flowing, there is a greater flow rate of charge; aka, current; and so the signal is amplified. The only thing is, the main voltage with the collector does not add to the small current that passes through. Rather, the voltage is there to keep the electrons moving after they go through the depletion zone of the transistor.


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You have drawn what is called as the follower. The output will follow the input. However at large input voltage swings you will expect clippings.


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Any electrical component has some kind of "resistance" - that is, it takes effort to move a current through it (leaving aside for a moment superconductors). We talk about "resistance" as a way to quantify this effort; for a simple resistor, the resistance has a constant value (at a given temperature) which means that the relationship between voltage and ...


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In principle, yes, but for clear air the scattering is very very weak, and the scattered light would probably be drowned out by other background sources, especially the blue sky. It would be easier at night. If the air is not clear, but instead is carrying dust or water droplets or smoke, the beam would be easily visible and recordable, again much more ...


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Yes The image below shows the Keck telescope's laser guide star. It is designed to excite sodium atoms in the mesosphere. These excited sodium atoms flouresce and act as an artificial star which allows the telescope to correct for optical aberrations caused by Earth's atmosphere.


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I think everyone must be right. (I'm certainly not going to contradict two-time physics Nobel Laureate John Bardeen.) Schottky diodes have very short reverse-recovery times (switching from the conducting to the blocking state), so there can't be any significant minority-carrier currents, because it's extracting those minority carriers that slows down the ...



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