The very word emitter explains this. Emitter needs more carriers to get emitted by it. Hence doping has to be heavy.
Uniformly doped refers to a material in which the dopant atoms are evenly distributed throughout the entire volume of the material. This even distribution helps in ensuring consistent electrical properties and behavior across the material.
The emitter in a solar cell is a region where doping is done to create a p-n junction. It helps in generating an electric field that separates the electrons and holes, allowing for the conversion of light energy into electricity. The emitter typically has a higher concentration of dopants compared to the base region of the solar cell.
The emitter bias circuit is called self-bias because the bias voltage across the emitter-resistor is based on the transistor's own characteristics. The bias voltage adjusts itself based on the varying collector current to stabilize the operating point of the transistor. It is a self-adjusting mechanism that helps maintain a stable bias point for the transistor.
In an RC phase shift oscillator, one emitter follower stage is typically used to provide the required phase shift. In a Wien bridge oscillator, two emitter followers are used to achieve the required feedback and oscillation.
To create an ultrasonic wave emitter to repel bats, you can use commercially available ultrasonic repellers specifically designed for this purpose. These devices emit high-frequency sound waves that are unpleasant for bats, causing them to leave the area. Ensure that the emitter is placed strategically to cover the target area effectively.
Emitter is heavily doped because to provide charge carriers to Base & Collector region, Base and Collectors are lightly doped because to accept those charge carriers.
base
3: emitter, base, collectorThere are three regions but to be absolutely picky I think only two of them need be doped.Nope: they MUST be doped NPN or PNP. If any are undoped it will not function as a transistor.
Zener diode is heavily doped pn junction diode.
The terminals of a BJT (bipolar junction transistor) are the emitter, base, and collector. One common method to identify these terminals is to look at the physical package of the transistor. The emitter is usually connected to the most heavily doped region and is often indicated on the package. The base is usually the middle terminal, and the collector is often connected to the remaining terminal.
The bipolar junction transistor is a current operated device with three terminals, emitter, base, and collector. There are two varieties, NPN and PNP. In the NPN variety, if the base is more positive than the emitter and that junction is conducting (greater than typically 0.7 volts), then the current through that junction will control a larger current through the collector emitter junction, when the collecter is also more positive than the emitter and that junction is also conducting. In the PNP variety, the same thing applies, but reverse positive to negative. You can operate in linear mode, where the base current controls the collector current, or you can operate in saturated (switched) mode, where the base current is enough to pass any collector current. This is all dependent on gain, also known as hFe, or beta.
Zener diodes are heavily doped to create a narrow depletion region, allowing them to operate in the reverse breakdown region where they exhibit the Zener effect. This effect causes the diode to conduct in reverse bias at a specific voltage, ideal for voltage regulation applications.
In the early 70s, making large resistors was expensive in silicon area. The diffusion used to make the bases of NPN transistors had the highest resistance per silicon area. When making NPN transistors, the emitter is diffused over the top of a base region. The resistance in this sub-surface base region which is "pinched" between an N doped epi collector below it and a N doped emitter region above it can have 10 times the normal base resistance. It was often used in non critical applications to save on silicon die size.
Bipolar transistor current gain is also called "Beta," or the h-parameter "hfe." beta = current_out / current_in The beta of a BJT is mostly determined by the thickness of the Base region, and by the excess doping in the Emitter relative to the Base. A thin Base and a heavily-doped Emitter leads to a high value for current gain. In a BJT, beta = Ic / Ib In a FET, beta is usually taken as infinity, since no current flows in or out of the gate. Beta is an impirical number. It means nothing unless the Ic is known or the load. It can have a beta from 1000 to 10 it all depends on the load.
Semiconductors have bulk resistivity in the range of 10-4 ohm-cm (heavily doped) to 103 ohm-cm (undoped, or intrinsic).
when the p-n junction is heavily doped p-n junction diode has very sharp breakdown voltage.
The width of the base is very thin to increase the majority carrier concentration gradient in the base region thereby enhancing the diffusion current and also to reduce the number of majority carriers lost due to recombination in the base.