Crystal diode

Semiconductor silicon SI, the outermost four electrons, not easy to lose electrons and not easy to gain electrons, known as intrinsic semiconductor.

1. If the outermost 5-electron PI is added to pure silicon. Phosphorus outermost 5 electrons, equivalent to the original intrinsic semiconductor in an electron, the electron can move freely, the electron is negative, so it is called Negetive semiconductor, also called n-type semiconductor

2. If a little bit of boron B with the outermost three electrons is added to the intrinsic semiconductor, the intrinsic semiconductor is less than an electron, equivalent to some positions there are holes, the hole has the ability to get electrons, and the nature of the Positive charge is the same, then it is called a Positive semiconductor, also known as p-type semiconductor.

After p-type semiconductor and n-type semiconductor together, due to p-type semiconductor “hole concentration is high”, n-type semiconductor electron concentration is high, concentration of diffusion will occur, high concentration flows to low concentration, known asDiffusion movement.The n-type electrons flow to the P-type. But it does not diffuse indefinitely, and the electric field is built up along with the diffusion:N-type is positively charged, p-type is negatively charged, and the electric field force on electrons is directed from P-type to N-typeThe electric field then begins to constrain the diffusion motion. As the electric field builds up, the electrons in the N zone are less likely to reach the P zone. The more they spread out, the bigger the electric field becomes, and the electric field keeps pulling back the particles that are trying to spread out. This pulling back process is called drift motion. Eventually, it will reach dynamic equilibrium.This middle electric field is calledThe PN section

1. If given at this timeThe N region is positively charged, and the P region is negatively charged, exerting an electric field force of P->N on the electrons. The battery produces a cell in the same direction as the internal electric field, so the internal electric field will be stretched so that it is still in dynamic equilibrium, blocking the current2. If the electricity is turned on the other way,P is positive and N is negativeThe electric field generated by the battery is in the opposite direction to the internal electric field, which will compress the internal electric field. Once the electric field intensity of the external power source (the battery) is greater than the internal electric field, which completely overcomes the internal electric field, electrons can start flowing from N to PThe circuit conduction. This thing is called a diode. It’s calledCrystal tube. To overcome this internal electric field, you generally need to0.7 VThe voltage of theta, which is thetaThe on-voltage of a diode

Crystal triode

The outermost large is an N-type semiconductor, the middle is a P-type semiconductor, and the innermost is an N-type semiconductor, forming the triode shown below. Both PN surfaces produce a PN junction, which is the initial state of a triode.One of the n-region is positive and one of the n-region is negative. Since there are two back-to-back PN junctions between them, how can they be turned on when they are energizedIf a positive charge is applied to the P-type semiconductor and the voltage is greater than 0.7V, the PN junction between position 1 and position 2 is overcome, that is, the electricity is energized between 12, and the electrons of 1 flow to 2.

By observing the 3d model of the triode, it can be found that the P zone of no.2 in the middle is deliberately thin, while the N zone of no.1 is deliberately mixed with many elements of the outermost 5 electrons. The electron concentration is very high. Once no. 1 and No. 2 are energized, the electrons of No. 1 will instantly flood into No. 2. And since no. 2 is so thin, it’s hard to consume all the incoming electrons at once. At this point we’ll focus on numbers two and three. The PN junctions of 2 and 3 are also in dynamic equilibrium, but the influx of electrons from number 2 breaks the dynamic equilibrium, and the electrons from number 2 start diffusing backward toward number 3. And intentionally do 3 big, electron density less than 1 at the same time, as a result, in no. 2 electronic soon be 3 gather up, due to no. 3, the positively charged, so 3 to collect electronic immediately got a quick xie hung tung road, after collecting electronic from 2, through the power of positive xie hong quickly, now, can think of 2 and 3 have electricity. Since the electrons pouring into 3 from 2 are actually coming from 1, you can assume that there’s a current going on between 1 and 3. At this point, the triode began to work. Because no.2 is very thin, the ability to consume from no.1 is limited, so the current is generally small. Because no.3 has a large space and strong ability to absorb electrons, the current is generally relatively large. The minimal signal change of No. 2 will lead to a huge change in the influx velocity of no. 1 electron, thus causing a huge change in the current between No. 1 and No. 3, so it is called crystal triode. 1 is connected to the negative pole, the main function is to emit electrons, known as the emitter. No. 3 is connected to the positive electrode, whose main function is to collect electrons, called the collector. No. 2 is connected to the positive terminal, which operates the raw signal like a valve, called the base.

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Mosfet (MosFET)

Technical details: Between the following stack of semiconductor materials and metals 1,2, and 3, there is a thin layer of silicon dioxide that is not a conductor, so conductor 2 is actually separate from the underlying semiconductor, but metals 1 and 3 do come into direct contact with the two N-type semiconductors through the silicon dioxide.

No. 2 P is negative, at this time no. 3 N-type semiconductor, if you want to conduct electricity, you need to reverse attack the PN node, which is impossible, at this time the pipe is closed. If number 2 is now positively charged, the metal of number 2 passes through the silicon dioxide layer in the middle, creating a capacitor in the p-type semiconductor below. (Number 2 is positively charged, which generates an electric field below, which passes through the silicon dioxide layer and into the P-type semiconductor.) The P-type semiconductor then accumulates above the electric field. At this point, the p-type semiconductor on top of the number of electrons gradually outnumber the N-type, so the electrons began to diffuse back. Due to the semiconductor equivalent of an inversion, this part is called the antitype layer and the electrons quickly slip away as the positive electrode is connected to number 3. In contrast, the n-type semiconductor on the left, the same thing happens, but because metal 1 is connected to a negative electrode, instead of electrons flowing away, the negative electrode keeps feeding electrons into it to supply the current needed by metal 3, so that metal 1 and 3, under control of metal 2, form a circuit. No. 2 controls the conduction of the circuit like a fence, called the gate. The one that continuously supplies electrons is known as the source level. No. 3 of circuit conduction through the conductive channel of the reverse layer, known as the drain

The positives and negatives of the gate control the resistance of the circuit. If the positives are 1 and the negatives are 0, then everything in the circuit is controlled by 0 and 1 at the gate