A semiconductor diode is a non-linear electronic device with two conclusions. Depending on the internal structure, type, quantity and level of doping of the internal elements of the diode and the current-voltage characteristic, the properties of semiconductor diodes are different.

rectifier diode on basis p-n transition The basis of the rectifier diode is an ordinary electron-hole transition, the current-voltage characteristic of such a diode has a pronounced nonlinearity. In forward bias, the diode current is injection, large in magnitude, and represents the diffusion component of the majority carrier current. With reverse bias, the diode current is small in magnitude and represents the drift component of the minority carrier current. In the equilibrium state, the total current due to diffusion and drift currents of electrons and holes is equal to zero. Rice. Semiconductor diode parameters: a) current-voltage characteristic; b) the design of the VAC case is described by the equation

Rectification in a diode One of the main properties of a semiconductor diode based on p-n junction is a sharp asymmetry of the current-voltage characteristic: high conductivity with forward bias and low with reverse bias. This property of the diode is used in rectifier diodes. The figure shows a circuit illustrating the rectification of alternating current in a diode. - Rectification ratio of an ideal diode based on p-n junction.

Characteristic resistance There are two types of characteristic resistance of diodes: differential resistance rD and DC resistance RD. Differential resistance is defined as DC resistance In the forward section of the current-voltage characteristic, the DC resistance is greater than the differential resistance RD > rD, and in the reverse section it is less than RD rD, and in the reverse section it is less than RD

Zener diodes A zener diode is a semiconductor diode whose current-voltage characteristic has a region of sharp current-voltage dependence in the reverse section of the current-voltage characteristic. The CVC of the zener diode has the form shown in the figure. When the voltage on the zener diode, called the stabilization voltage Ustab, is reached, the current through the zener diode increases sharply. The differential resistance Rdiff of an ideal zener diode tends to 0 in this section of the I-V characteristic, in real devices the value of Rdiff is: Rdif 2 50 Ohm.

The main purpose of the zener diode is to stabilize the voltage at the load, with a changing voltage in the external circuit. In this regard, a load resistance is included in series with the zener diode, damping the change in the external voltage. Therefore, a zener diode is also called a reference diode. The stabilization voltage Ustab depends on the physical mechanism that causes a sharp dependence of the current on the voltage. There are two physical mechanisms responsible for such a dependence of current on voltage - avalanche and tunneling breakdown of the p n junction. For zener diodes with a tunnel breakdown mechanism, the stabilization voltage Ustab is small and is less than 5 volts: Ustab is 8 V.

Varicaps A varicap is a semiconductor diode whose operation is based on the dependence of the barrier capacity p-n transition from reverse voltage. Varicaps are used as elements with an electrically controlled capacitance in frequency tuning circuits of an oscillatory circuit, frequency division and multiplication, frequency modulation, controlled phase shifters, etc. In the absence of external voltage, a potential barrier and an internal electric field exist in the p-n junction. If a reverse voltage is applied to the diode, then the height of this potential barrier will increase. The external reverse voltage repels electrons deep into the n-region, resulting in an expansion of the depleted area p-n transition, which can be represented as the simplest flat capacitor, in which the boundaries of the region serve as the plates. In this case, in accordance with the formula for the capacitance of a flat capacitor, with an increase in the distance between the plates (caused by an increase in the value of the reverse voltage), the capacitance of the p-n junction will decrease. This decrease is limited only by the thickness of the base, beyond which the transition cannot expand. After reaching this minimum, the capacitance does not change with increasing reverse voltage.

In an n+ type semiconductor, all states in the conduction band up to the Fermi level are occupied by electrons, while in a p+ type semiconductor they are occupied by holes. Band diagram of a p+ n+ junction formed by two degenerate semiconductors: Let us calculate the geometric width of a degenerate p n junction. We will assume that in this case the asymmetry of the p n transition is preserved (p+ is a more heavily doped region). Then the width of the p+ n+ transition is small: We can estimate the De Broglie wavelength of an electron from simple relations:

Thus, the geometric width of the p+ n+ transition turns out to be comparable with the de Broglie wavelength of the electron. In this case, in a degenerate p+ n+ transition, one can expect manifestations quantum mechanical effects, one of which is tunneling through a potential barrier. For a narrow barrier, the probability of tunneling through the barrier is nonzero. A reversed diode is a tunnel diode without a negative differential resistance section. The high nonlinearity of the current–voltage characteristic at low voltages near zero (on the order of microvolts) makes it possible to use this diode for detecting weak signals in the microwave range. Volt-ampere characteristic of a germanium inverted diode a) total current-voltage characteristic; b) reverse section of the CVC at different temperatures

Diode rectifiers Three-phase rectifier Larionov A.N. on three half-bridges Diodes are widely used to convert alternating current into direct current (more precisely, into unidirectional pulsating). A diode rectifier or diode bridge (that is, 4 diodes for a single-phase circuit (6 for a three-phase half-bridge circuit or 12 for a three-phase full-bridge circuit) connected to each other in a circuit) is the main component of power supplies for almost all electronic devices. A diode three-phase rectifier according to the scheme of A. N. Larionov on three parallel half-bridges is used in automobile generators, it converts the three-phase alternating current of the generator into the direct current of the vehicle's on-board network. The use of an alternator in combination with a diode rectifier instead of a DC generator with a brush-collector assembly made it possible to significantly reduce the size of an automobile generator and increase its reliability. Some rectifiers still use selenium rectifiers. This is due to the peculiarity of these rectifiers that when the maximum allowable current is exceeded, selenium burns out (in sections), which does not (to a certain extent) lead to either a loss of rectifier properties or a short circuit - breakdown. High-voltage rectifiers use selenium high-voltage columns from a plurality of series-connected selenium rectifiers and silicon high-voltage columns from a plurality of series-connected silicon diodes. Diode Detectors Diodes, in combination with capacitors, are used to extract low frequency modulation from an AM RF signal or other modulated signals. Diode detectors are used in almost all [source not specified 180 days] radio receivers: radios, televisions, etc. The square section of the current-voltage characteristic of the diode is used. Diode protection Diodes are also used to protect various devices from reverse polarity, etc. There is a well-known diode protection scheme for DC circuits with inductances against surges when the power is turned off. The diode is connected in parallel with the coil so that in the "working" state the diode is closed. In this case, if the assembly is turned off abruptly, a current will appear through the diode and the current will decrease slowly (the induction emf will be equal to the voltage drop across the diode), and there will be no powerful voltage surge leading to sparking contacts and burning semiconductors. Diode switches Used for switching high-frequency signals. The control is carried out by direct current, the separation of the RF and control signal using capacitors and inductances. Diode Spark Protection This does not exhaust the use of diodes in electronics, but other circuits tend to be very specialized. Special diodes have a completely different area of ​​applicability, so they will be discussed in separate articles.

Presentation on the topic: "Semiconductor diodes" Completed by: Barmin R.A. Gelzin I.E. A semiconductor diode is a non-linear electronic device with two terminals. Depending on the internal structure, type, quantity and level of doping of the internal elements of the diode and the current-voltage characteristic, the properties of semiconductor diodes are different. We will consider the following types of diodes: rectifier diodes based on p-n junction, zener diodes, varicaps, tunnel and reverse diodes. J J s (e VG 1) Rectifier diode based on p-n junction The basis of the rectifier diode is an ordinary electron-hole junction, the current-voltage characteristic of such a diode has a pronounced nonlinearity. In forward bias, the diode current is injection, large in magnitude, and represents the diffusion component of the majority carrier current. With reverse bias, the diode current is small in magnitude and represents the drift component of the minority carrier current. In the equilibrium state, the total current due to diffusion and drift currents of electrons and holes is equal to zero. Rice. Semiconductor diode parameters: a) current-voltage characteristic; b) the design of the I-V characteristic is described by the equation J J s (e VG 1) Rectification in the diode One of the main properties of a semiconductor diode based on a p-n junction is a sharp asymmetry of the current-voltage characteristic: high conductivity with forward bias and low with reverse. This property of the diode is used in rectifier diodes. The figure shows a circuit illustrating the rectification of alternating current in a diode. - Rectification ratio of an ideal diode based on p-n junction. Characteristic resistance There are two types of characteristic resistance of diodes: differential resistance rD and DC resistance RD. The differential resistance is defined as the DC resistance RD U I U I 0 (e U 1)< rD. Стабилитроны Стабилитрон - это полупроводниковый диод, вольт-амперная характеристика которого имеет область резкой зависимости тока от напряжения на обратном участке вольт-амперной характеристики. ВАХ стабилитрона имеет вид, представленный на рисунке При достижении напряжения на стабилитроне, называемого напряжением стабилизации Uстаб, ток через стабилитрон резко возрастает. Дифференциальное сопротивление Rдиф идеального стабилитрона на этом участке ВАХ стремится к 0, в реальных приборах величина Rдиф составляет значение: Rдиф 250 Ом. Основное назначение стабилитрона – стабилизация напряжения на нагрузке, при изменяющемся напряжении во внешней цепи. В связи с этим последовательно со стабилитроном включают нагрузочное сопротивление, демпфирующее изменение внешнего напряжения. Поэтому стабилитрон называют также опорным диодом. Напряжение стабилизации Uстаб зависит от физического механизма, обуславливающего резкую зависимость тока от напряжения. Различают два физических механизма, ответственных за такую зависимость тока от напряжения, – лавинный и туннельный пробой p-n перехода. Для стабилитронов с туннельным механизмом пробоя напряжение стабилизации Uстаб невелико и составляет величину менее 5 вольт: Uстаб < 5 В. Для стабилитронов с лавинным механизмом пробоя напряжение стабилизации обычно имеет большие значения и составляет величину более 8 вольт: Uстаб > 8 V. Varicaps Varicaps - a semiconductor diode, the operation of which is based on the dependence of the barrier capacitance of the p-n junction on the reverse voltage. Varicaps are used as elements with an electrically controlled capacitance in frequency tuning circuits of an oscillatory circuit, frequency division and multiplication, frequency modulation, controlled phase shifters, etc. In the absence of external voltage, a potential barrier and an internal electric field exist in the p-n junction. If a reverse voltage is applied to the diode, then the height of this potential barrier will increase. The external reverse voltage repels electrons deep into the n-region, as a result of which the depleted region of the p-n junction expands, which can be represented as the simplest flat capacitor, in which the boundaries of the region serve as the plates. In this case, in accordance with the formula for the capacitance of a flat capacitor, with an increase in the distance between the plates (caused by an increase in the value of the reverse voltage), the capacitance of the p-n junction will decrease. This decrease is limited only by the thickness of the base, beyond which the transition cannot expand. After reaching this minimum, the capacitance does not change with increasing reverse voltage. A tunnel diode is a semiconductor diode based on a p + -n + junction with heavily doped regions, in the straight section of the current-voltage characteristic of which an n-shaped dependence of current on voltage is observed. In an n+-type semiconductor, all states in the conduction band up to the Fermi level are occupied by electrons, and in a p+-type semiconductor, by holes. Band diagram of a p+-n+ junction formed by two degenerate semiconductors: Let's calculate the geometric width of a degenerate p-n junction. We will assume that in this case the asymmetry of the p-n junction is preserved (p + is a more heavily doped region). Then the width of the p+-n+ transition is small: 2 s 0 2 0 W 2 s 0 E g qN D 2 1 10 qN D 12 1.6 10 19 1 6 ~ 10 ñ ~ 100 Å Let us estimate the De Broglie wavelength of the electron from simple relations: E 2 2 2 2m 2 kT ; 2 mkT h 2 1 h 2 mkT 2 9.1 10 31 1. 38 10 6. 3 10 34 23 300 ~ 140 Å Thus, the geometric width of the p+-n+ transition is comparable to the de Broglie wavelength of the electron. In this case, in a degenerate p+-n+ transition, one can expect manifestations of quantum mechanical effects, one of which is tunneling through a potential barrier. For a narrow barrier, the probability of tunneling through the barrier is nonzero. A reversed diode is a tunnel diode without a negative differential resistance section. The high nonlinearity of the current-voltage characteristic at low voltages near zero (on the order of microvolts) makes it possible to use this diode for detecting weak signals in the microwave range. Current-voltage characteristic of a germanium inverted diode a) full current-voltage characteristic; b) reverse section of the CVC at different temperatures

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Presentation on the topic: Diode

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tunnel diode. The first work confirming the reality of creating tunnel devices was devoted to the tunnel diode, also called the Esaki diode, and published by L. Esaki in 1958. Esaki, in the process of studying the internal field emission in a degenerate germanium p-n junction, discovered an "anomalous" current-voltage characteristic: the differential resistance in one of the sections of the characteristic was negative. He explained this effect with the help of the concept of quantum mechanical tunneling and at the same time obtained an acceptable agreement between theoretical and experimental results.

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tunnel diode. A tunnel diode is a semiconductor diode based on a p + -n + junction with heavily doped regions, in the straight section of the current-voltage characteristic of which an n-shaped dependence of current on voltage is observed. As is known, impurity energy bands are formed in semiconductors with a high concentration of impurities. In n-semiconductors, this band overlaps with the conduction band, and in p-semiconductors, with the valence band. As a result, the Fermi level in n-semiconductors with a high impurity concentration lies above the Ec level, and in p-semiconductors below the Ev level. As a result, within the energy range DE=Ev-Ec, any energy level in the conduction band of an n-semiconductor can correspond to the same energy level behind the potential barrier, i.e. in the valence band of a p-semiconductor.

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tunnel diode. Thus, particles in n and p semiconductors with energy states within the DE interval are separated by a narrow potential barrier. In the valence band of a p-semiconductor and in the conduction band of an n-semiconductor, some of the energy states in the DE interval are free. Consequently, through such a narrow potential barrier, on both sides of which there are unoccupied energy levels, the tunneling motion of particles is possible. When approaching the barrier, the particles experience reflection and in most cases return back, but there is still a probability of detecting a particle behind the barrier; as a result of the tunnel transition, the tunneling current density j t0 is also nonzero. Let's calculate what the geometric width of the degenerate p-n junction is. We will assume that in this case the asymmetry of the p-n junction is preserved (p + is a more heavily doped region). Then the width of the p+-n+ transition is small: We estimate the De Broglie wavelength of the electron from simple relations:

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tunnel diode. The geometric width of the p+-n+ transition is comparable to the de Broglie wavelength of the electron. In this case, in a degenerate p+-n+ transition, one can expect manifestations of quantum-mechanical effects, one of which is tunneling through a potential barrier. With a narrow barrier, the probability of tunneling through the barrier is non-zero!!!

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tunnel diode. Currents in a tunnel diode. At equilibrium, the total current through the junction is zero. When a voltage is applied to the junction, electrons can tunnel from the valence band to the conduction band or vice versa. For the tunneling current to flow, the following conditions must be met: 1) the energy states on the side of the junction from which the electrons tunnel must be filled; 2) on the other side of the transition, the energy states with the same energy must be empty; 3) the height and width of the potential barrier must be small enough for there to be a finite probability of tunneling; 4) the quasi-momentum must be conserved. tunnel diode.swf

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tunnel diode. As parameters, voltages and currents characterizing the singular points of the I–V characteristics are used. The peak current corresponds to the maximum CVC in the region of the tunnel effect. The voltage Up corresponds to the current Ip. The valley current Iv and Uv characterize the I–V characteristics in the region of the current minimum. The voltage of the solution Upp corresponds to the value of the current Ip on the diffusion branch of the characteristic. The falling section of the dependence I=f(U) is characterized by a negative differential resistance rД= -dU/dI, the value of which can be determined with some error by the formula

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reversed diodes. Let us consider the case when the Fermi energy in electron and hole semiconductors coincides or is at a distance of ± kT/q from the bottom of the conduction band or the top of the valence band. In this case, the current-voltage characteristics of such a diode with reverse bias will be exactly the same as that of a tunnel diode, that is, with an increase in the reverse voltage, there will be a rapid increase in the reverse current. As for the current with forward bias, the tunneling component of the I–V characteristic will be completely absent due to the fact that there are no completely filled states in the conduction band. Therefore, when forward biased in such diodes to voltages greater than or equal to half the band gap, there will be no current. From the point of view of a rectifier diode, the current-voltage characteristic of such a diode will be inverse, that is, there will be high conductivity with reverse bias and low with forward bias. In this regard, this type of tunnel diodes are called inverted diodes. Thus, a reversed diode is a tunnel diode without a section with a negative differential resistance. The high nonlinearity of the current–voltage characteristic at low voltages near zero (of the order of microvolts) makes it possible to use this diode for detecting weak signals in the microwave range.

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Transition processes. With rapid voltage changes across a semiconductor diode based on normal p-n transition, the value of the current through the diode, corresponding to the static current-voltage characteristic, is not immediately established. The process of establishing the current during such switching is usually called the transient process. Transient processes in semiconductor diodes are associated with the accumulation of minority carriers in the base of the diode when it is directly turned on and their absorption in the base with a rapid change in the polarity of the voltage across the diode. Since there is no electric field in the base of a conventional diode, the movement of minority carriers in the base is determined by the laws of diffusion and occurs relatively slowly. As a result, the kinetics of carrier accumulation in the base and their dissipation affect the dynamic properties of diodes in the switching mode. Consider the change in current I when switching the diode from forward voltage U to reverse voltage.

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Transition processes. In the stationary case, the current in the diode is described by the equation After the completion of transients, the current in the diode will be equal to J0. Consider the kinetics of the transition process, that is, the change current p-n transition when switching from direct to reverse voltage. When a diode is forward biased on the basis of an asymmetric p-n junction, non-equilibrium holes are injected into the base of the diode. The change in time and space of nonequilibrium injected holes in the base is described. continuity equation:

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Transition processes. At time t = 0, the distribution of injected carriers in the base is determined from the diffusion equation and has the form: From general provisions it is clear that at the moment of switching the voltage in the diode from direct to reverse, the value of the reverse current will be significantly greater than the thermal current of the diode. This will happen because the reverse current of the diode is due to the drift component of the current, and its value, in turn, is determined by the concentration of minority carriers. This concentration is significantly increased in the base of the diode due to the injection of holes from the emitter and is described at the initial moment by the same equation.

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Transition processes. As time passes, the concentration of nonequilibrium carriers will decrease, and, consequently, the reverse current will also decrease. During the time t2, called the recovery time of the reverse resistance, or the resorption time, the reverse current will come to a value equal to the thermal current. To describe the kinetics of this process, we write the boundary and initial conditions for the continuity equation in the following form. At time t = 0, the equation for the distribution of injected carriers in the base is valid. When a stationary state is established at the moment of time, the stationary distribution of nonequilibrium carriers in the base is described by the relation:

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Transition processes. The reverse current is due only to the diffusion of holes to the boundary of the space charge region of the p-n junction: The procedure for finding the kinetics of the reverse current is as follows. Taking into account the boundary conditions, the continuity equation is solved and the dependence of the concentration of nonequilibrium carriers in the base p(x,t) on time and coordinate is found. The figure shows the coordinate dependences of the concentration p(x,t) at different times. Coordinate dependences of the concentration p(x,t) at different times

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Transition processes. Substituting the dynamic concentration p(x,t), we find the kinetic dependence of the reverse current J(t). The dependence of the reverse current J(t) has the following form: Here, is an additional error distribution function equal to the First expansion additional function errors has the form: Let us expand the function in a series in cases of small and large times: t > p. We get: From this relation it follows that at the moment t = 0 the value of the reverse current will be infinitely large. The physical limit for this current will be the maximum current that can flow through the ohmic resistance of the base of the diode rB at reverse voltage U. The value of this current, called the cutoff current Jav, is equal to: Jav = U/rB. The time during which the reverse current is constant is called the cutoff time.

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Transition processes. For pulsed diodes, the cutoff time τcp and the recovery time τv of the reverse resistance of the diode are important parameters. There are several ways to reduce their value. First, the lifetime of nonequilibrium carriers in the diode base can be reduced by introducing deep recombination centers in the quasi-neutral volume of the base. Second, you can make the base of the diode thin so that non-equilibrium carriers recombine on the back side of the base. perpr_pn.swf Reverse current versus time when switching the diode

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Electron-hole transition. Transistor

An electron-hole junction (or n-p-junction) is the contact area of ​​two semiconductors with different types conductivity.

When two semiconductors of n- and p-types come into contact, the diffusion process begins: holes from the p-region go to the n-region, and electrons, on the contrary, from the n-region to the p-region. As a result, the electron concentration decreases in the n-region near the contact zone and a positively charged layer appears. In the p-region, the concentration of holes decreases and a negatively charged layer appears. A double electric layer is formed at the boundary of semiconductors, the electric field of which prevents the process of diffusion of electrons and holes towards each other.

The boundary region between semiconductors with different types of conductivity (blocking layer) usually reaches a thickness of the order of tens and hundreds of interatomic distances. The space charges of this layer create between the p- and n-regions a blocking voltage U c, approximately equal to 0.35 V for germanium n-p junctions and 0.6 V for silicon ones.

Under conditions of thermal equilibrium in the absence of an external electric voltage, the total current through the electron-hole junction is zero.

If the n-p junction is connected to the source so that the positive pole of the source is connected to the p-region, and the negative pole to the n-region, then the electric field strength in the blocking layer will decrease, which facilitates the transition of the main carriers through the contact layer. Holes from the p-region and electrons from the n-region, moving towards each other, will cross the n-p-junction, creating a current in forward direction. The current through the n - p -junction in this case will increase with increasing source voltage.

If a semiconductor with an n-p junction is connected to a current source so that the positive pole of the source is connected to the n-region, and the negative pole to the p-region, then the field strength in the blocking layer increases. Holes in the p-region and electrons in the n-region will shift away from the n–p junction, thereby increasing the concentration of minority carriers in the barrier layer. The current through the n - p -junction practically does not go. A very small reverse current is due only to the intrinsic conductivity of semiconductor materials, i.e., the presence of a small concentration of free electrons in the p-region and holes in the n-region. The voltage applied to the n - p -junction in this case is called reverse.

The ability of the n - p junction to pass current in almost only one direction is used in devices called semiconductor diodes. Semiconductor diodes are made from silicon or germanium crystals. During their manufacture, an impurity is melted into a crystal with a certain type of conductivity, which provides a different type of conductivity. Semiconductor diodes have many advantages compared to vacuum diodes - small size, long service life, mechanical strength. A significant disadvantage of semiconductor diodes is the dependence of their parameters on temperature. Silicon diodes, for example, can only operate satisfactorily over a temperature range of -70°C to 80°C. For germanium diodes, the operating temperature range is somewhat wider.

Semiconductor devices with not one but two n-p junctions are called transistors. The name comes from a combination English words: transfer - transfer and resistor - resistance. Typically, germanium and silicon are used to create transistors. Transistors are of two types: p-n-p-transistors and n-p-n-transistors.

The germanium transistor p - n - p -type is a small plate of germanium with a donor impurity, i.e., from an n-type semiconductor. In this plate, two regions with an acceptor impurity, i.e., regions with hole conduction, are created.

In an n - p - n-type transistor, the main germanium plate has p-type conductivity, and the two regions created on it have n-type conductivity.

The transistor plate is called the base (B), one of the areas with the opposite type of conductivity is called the collector (K), and the second is called the emitter (E). Typically, the volume of the collector is larger than the volume of the emitter.

IN legend different structures, the emitter arrow shows the direction of current through the transistor.

Inclusion in the circuit of the transistor p - n - p-structure The "emitter-base" transition is switched on in the forward (throughput) direction (emitter circuit), and the "collector-base" transition is switched on in the blocking direction (collector circuit).

When the emitter circuit is closed, holes - the main charge carriers in the emitter - pass from it to the base, creating a current I e in this circuit. But for holes that have fallen into the base from the emitter, the n - p -junction in the collector circuit is open. Most of the holes are captured by the field of this transition and penetrate into the collector, creating a current I k.

In order for the collector current to be practically equal to the emitter current, the base of the transistor is made in the form of a very thin layer. When the current in the emitter circuit changes, the current in the collector circuit also changes.

If an alternating voltage source is included in the emitter circuit, then an alternating voltage also appears on the resistor R, included in the collector circuit, the amplitude of which can be many times greater than the amplitude of the input signal. Therefore, the transistor acts as an AC voltage amplifier.

However, such a transistor amplifier circuit is inefficient, since there is no current amplification in it, and the entire emitter current Ie flows through the input signal sources. In real transistor amplifier circuits, an AC voltage source is turned on so that only a small base current flows through it I b \u003d I e - I k. Small changes in the base current cause significant changes in the collector current. The current gain in such circuits can be several hundred.

Currently, semiconductor devices are extremely widely used in radio electronics. Modern technology allows the production of semiconductor devices - diodes, transistors, semiconductor photodetectors, etc. - with a size of several micrometers. A qualitatively new stage in electronic technology was the development of microelectronics, which is engaged in the development of integrated circuits and the principles of their application.

An integrated circuit is a collection of a large number of interconnected elements - ultra-small diodes, transistors, capacitors, resistors, connecting wires, made in a single technological process on one crystal. A 1 cm 2 microcircuit can contain several hundred thousand microelements. The use of microcircuits has led to revolutionary changes in many areas of modern electronic technology. This is especially evident in the field of electronic computing. Bulky computers containing tens of thousands of electron tubes and occupying entire buildings have been replaced by personal computers.

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