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In bipolar junction transistor (BJT), which layer has highest level of doping?

In bipolar junction transistor (BJT), which layer has highest level of doping? Correct Answer Emitter

Bipolar Junction Transistor:

Basically, the bipolar junction transistor consists of two back-to-back P-N junctions manufactured in a single piece of a semiconductor crystal.

These two junctions give rise to three regions called emitter, base, and collector. As shown in Fig. junction transistor is simply a sandwich of one type of semiconductor material between two layers of the other type.

The emitter, base, and collector are provided with terminals that
are labeled as E, B, and C.

The two junctions are: emitter-base (E/B) junction and collector-base (C/B) junction.

1. Emitter:

It is more heavily doped than any of the other regions because its main function is to supply majority charge carriers (either electrons or holes) to the base.

2. Base:

It forms the middle section of the transistor. It is very thin (10–6 m) as compared to either the emitter or collector and is very lightly doped.

3. Collector:

Its main function (as indicated by its name) is to collect the majority of charge carriers coming from the emitter and passing through the base.

In most transistors, the collector region is made physically larger than the emitter region because it has to dissipate much greater power.

In Short:

The order of width is

wcollector > wemitter > wBase

The order of doping is

nemitter > ncollector > nbase

Related Questions

For transistor action (a) Base, emitter, and collector regions should have similar size and doping concentrations. (b) The base region must be very thin and lightly doped. (c) The emitter-base junction is forward biased and the base-collector junction is reverse biased. (d) Both the emitter-base junction as well as the base-collector junction are forward biased. Which one of the following pairs of statements is correct?
Some small cubes of same height 7 cm but variable length and width are put inside a large cuboid of height 21 cm. Length and width of cuboid is 32 cm and 24 cm, respectively. Small cubes are put such that cubes at the bottom most layer is of similar base area; second layer contains all the cubes of similar base area and third layer have all the cubes of similar base area. Which of the following statement(s) given below is / are TRUE? A: If side of each small cubes at bottom most layer is 8 cm, then maximum number of small cubes that can be put at bottom most layer is 12. B: If maximum of 48 cubes can be put at second layer, then side of each cube at second layer is 6 cm. C: If side of each small cubes at third layer is 1.6 cm, then maximum number of small cubes that can be put at third layer is 300.
When both the junctions of bipolar junction transistor (BJT) are in forward biased, then in which region BJT will operate?
In the following question, two statements are given each followed by two conclusions I and II. You have to consider the statements to be true even if they seem to be at variance from commonly known facts. You have to decide which of the given conclusions, if any, follows from the given statements. Statement: (I) 28 athletes are facing legal cases due to doping incidents. (II) The new wave of Olympic doping cases is based on evidences. Conclusions: (I) The report of doping is based on the test that happen. (II) Doping practice is very common these days among athletes.
In the following question, two statements are given each followed by two conclusions I and II. You have to consider the statements to be true even if theyseem to be at variance from commonly known facts. You have to decide which of the given conclusions, if any, follows from the given statements.
Statement:
(I) 28 athletes are facing legal cases due to doping incidents.
(II) The new wave of Olympic doping cases is based on evidences.
Conclusions:
(I) The report of doping is based on the test that happen.
(II) Doping practice is very common these days among athletes.
Consider the following statements regarding an N-P-N Bipolar Junction Transistor: 1. Emitter diode is forward biased and the collector diode is reverse biased 2. Emitter has many free electrons 3. Free electrons are injected into the base and pass through the collector 4. Depletion layers around junction J1 and J2 of BJT are widened. Which of the above statements are correct?
Choose the correct statement(s) i) The gate circuit impedance of MOSFET is higher than that of a BJT ii) The gate circuit impedance of MOSFET is lower than that of a BJT iii) The MOSFET has higher switching losses than that of a BJT iv) The MOSFET has lower switching losses than that of a BJT
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Which of the following conditions must be satisfied for a transistor to be in saturation? 1. Its collector to base junction should be under forward bias 2. Its collector to base junction should be under reverse bias 3. Its emitter to base junction should be under reverse bias 4. Its emitter to base junction should be under forward bias Which of the above conditions are correct?
A transistor is used in common emitter mode as an amplifier. Then a. The base-emitter junction is forward biased b. The base-emitter junction is reverse biased  c. The input signal is connected in series with the voltage applied to the base-emitter junction  d. The input signal is connected in series with the voltage applied to bias the base-collector junction Which of the following statement is true?