# Tag Info

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Is a hole in a conductor the same thing as a positive ion? YES. The term "hole" has become an established part of semiconductor vocabulary ever since Dr. Shockley published his treatise, "Electrons and Holes in Semiconductors" in 1950. However,"hole" is not a real subatomic particle. It is a convenient fiction which helps ...

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For DC analysis, start with the model of your reference: simulate this circuit – Schematic created using CircuitLab R_L is omitted, because it is an external component, load To reverse bias a photodiode, you use a network like this (transimpedance amplifier): simulate this circuit Inverting a V_bias polarity, you can also try and use this opamp ...

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This circuit is just the photodiode model and a load resistance. No bias network. The ideal diode is there because this is a photodiode. Which means that if you forward bias it, a lot of compoments gets bypassed, but when you reverse bias it those components come into play. The shunt resistance is really high. It's basically the resistance across the PN ...

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Since the graph of concentration is a negative gradient,the diffusion current due to electrons has negative sign. Considering the negative gradient, it becomes positive The diffusion current due to holes has a positive sign. Considering the negative gradient, it becomes negative.

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"one could conceive of means to extract work from an equilibrium situation by emitting electrons and then reabsorbing them an infinitesimal distance away where E0 had changed value". What does this mean? In physics, the vacuum level refers to the energy of a free stationary electron that is outside of any material (it is in a perfect vacuum). It ...

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Satellites in orbit use HeatPipes to move heat from interior to the exterior, to dump heat into the universe. They have wicking lining the pipe's interior wall, for the liquid to return to the interior. The vaporized gas moves thru the center of the HeatPipe, from the hot electronics ("hot" being relative) to the cold of the craft's outer wall. ...

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The main advantage of using IGBTs and MOSFETs over thyristors is not their smaller size (I honestly don't know if they even are smaller for the same power-handling capacity) but their higher efficiency and greater controllability. Thyristors have always had a flaw that they are very difficult to turn off; it requires waiting for the next mains zero crossing ...

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The process you are describing equalizes the Fermi level across the junction. Connecting wires equalizes the Fermi levels of the wires. The relative Fermi level is what a voltmeter reads, so a voltmeter connected in place of your resistor would read zero volts. There is no voltage to drive a current through your resistor. The detailed physics here is a bit ...

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If you take the field from any point-like charge -- an electron or hole -- and integrate it around any loop, the total field along the loop will add up to zero. The field from any distribution of such charges, integrated around a loop, is the sum of the field from all of the point charges. They all sum to 0 individually, so you get 0 when you add them all ...

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This circuit has three dissimilar materials: two doped semiconductor regions, and a wire (we can allow the resistor to be a wirewound type, so it's just... part of the wire). That means there are three junctions. While the metal joints are perhaps not semiconductor diodes, they ARE subject to the same charge-diffusion boundaries at the joint, and even ...

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For the time being I would forget about electron and hole movement/attraction, and consider simply how many electrons and holes there are. P-type and n-type materials are not determined by the position of the bands as such, more so defined by the 'majority carrier' in the material, i.e. in an n-type semiconductor the material has been doped by additional ...

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With VCC floating, there is a resistive path between input and output. And the Cob further obliges the collector to track the base movement.

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The best answer will be to simulate with VCC=0V and the likely range of input voltages and any potential signals from other sources on the output. You have to recognise that, absent power, you have two diodes present on the input side, and one on the output side. Potential effects from these include: Rectification, non-linearity, distortion of input signals ...

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Are you applying Vin still while Vcc is open? You'll measure a high-passed version of Vin through the resistive connection from the base to Vout (R1 + RL).

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The resistors RL, R1, and R2 connect the output terminals, so if the input signal amplitude is small you'll read 0 V DC between them. If the input is strong you may see a DC offset due to rectification of the input by the b-c junction. You'll also see some pass-through of the input AC signal. If the input amplitude is high enough to turn on the BJT's b-e and ...

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It will be 0V, due to the leakage current of the (N)PN junction (and, as The Photon remarks, the current through RL/R1/R1, although it would still be 0 without these)

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The holes (and free electrons) are constantly in the process of generation and re-combination. For intrinsic Silicon, the holes and electrons are equal in number since the (free) electrons are thermally excited from the valence band into the conduction band; i.e. for each electron in conduction band there is a hole generated in the valence band. The ...

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As other answers have clarified - copper is far more conductive than doped silicon. Regarding your question on N-type vs P-type; this is related to the concept of Electron and Hole Mobility. Mobility measures how fast electrons (or holes) can move through a material when an electric field is applied. At a simplistic level, for the same number of charge ...

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Doped silicon has various conductivities; some wafers [with 60 volt well_substrate sustaining voltage] are about 50 ohm_cm (that is, measured face to face across a 1cm cube, expect 50 ohms). Other materials may be 10 or 100X more conductive. But copper? A 1cm by 1cm square of PCB copper foil (35 microns thick) is only 0.000500 ohms (that is 500 microOhms) ...

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At room temperature, you got average thermal energy of "all" electrons = KT = 0.025eV. But energy of electrons always follow some non uniform distribution. Which implies that you may get some electrons containing higher and lower energies than that of average. And electrons nearer to valance band maxima will have sufficient energy to jump over the ...

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