Table of Contents
Why the width of base region is thin in transistor?
The base region in a transistor is made very thin so that there is a better conduction of majority carriers from emitter to collector through base. The base region in a transistor is doped lightly so that the number density of majority carriers (electrons in p-n and holes in n-p-n transistor) is low. …
Why is the base region of a transistor made thin as compared to the emitter and collector?
Reason: Due to thin base power gain and voltage gain is obtained by a transistor. In a transistor, the base is made extermely thin to reduce the combinations of holes and electrons. Under this conditions, most of the holes (or electrons) arriving from the emitter diffuses across base and reach the collector.
Why thickness of base is typically smaller than emitter and collector?
The collector has the weakest doping level so that the depletion layer will be large so that it can handle a large reverse voltage. The depletion region in the base will be smaller than the depletion region in the collector because the base has a higher doping level !
What is the function of base region of a transistor why this region is made thin and lightly doped?
Electron hole recombination takes place in the base region when emitter is forward biased. If the base is thin and lightly doped, it will have a small number density of majority charge carriers. This reduces the rate of electron hole recombination, necessary for a transistor action.
Why the thickness of the base region is minimum for a BJT?
The width of the region depends upon their doping. The base region is lightly doped so that width of the base is less. Collector region of a transistor is highly doped so collector region has more width than other two.
Why is Collector region wider than emitter region in BJT?
The collector region is the largest of all regions because it must dissipate more heat than the emitter or base regions. It is designed to be large because in order to dissipate all the heater, the extra surface area allows it to do so. The larger area ensures that it has more surface area to dissipate heat.
Is the base current in a transistor very small?
The base region is thin and lightly doped. Due to this, only a few of the large number of electrons emitted from heavily doped emitter recombined with holes in the base region, and hence base current is very low.
What does base current do in transistor?
The base current controls the collector current when the transistor is in the active region. A transistor is made up of two PN junctions, an emitter junction and a collector junction. The active region is when the emitter junction is forward biased and the collector junction is reverse biased.