What is minority carrier?

What is minority carrier?

minority carrier injection, in electronics, a process taking place at the boundary between p-type and n-type semiconductor materials, used in some types of transistors. Electrons are the more abundant, or majority, carrier in n-type materials, holes being the less abundant, or minority, carrier.

How are minority carriers formed?

When the pentavalent atoms such as Phosphorus or Arsenic are added to the intrinsic semiconductor, an n-type semiconductor is formed. In n-type semiconductor, large number of free electrons is present. Hence, holes are the minority charge carriers in the n-type semiconductor.

What is minority carrier extraction?

The concentration of minority carriers in a sample can be effectively decreased below its equilibrium value by an extraction process in which, (a) the minority carriers in the sample are swept out by an electric field in a time ≪lifetime, while (b) the minority carrier flow into the sample at the entry contact, is …

Which carrier is the minority carrier?

holes
semiconductor devices On the n side the electrons are the majority carriers, while the holes are the minority carriers.

What are the differences between majority and minority carriers?

The more abundant charge carriers are called majority carriers, which are primarily responsible for current transport in a piece of semiconductor. The less abundant charge carriers are called minority carriers; in n-type semiconductors they are holes, while in p-type semiconductors they are electrons.

What is minority carrier lifetime?

The minority carrier lifetime is defined as the average time it takes an excess minority carrier to recombine. It is strongly dependent on the magnitude and type of recombination processes in the semiconductor.

What happens if you inject minority carriers into the substrate?

When a p-n juction is forward biased, minority carriers are injected into the semiconductors on the two sides of the junction. These minority carriers diffuse about an eventually recombine with the majority carriers. The distribution of the minority carriers is described by the diffusion equation.

Why is minority carrier injection called low level injection?

Low-level injection conditions for a p–n junction, in physics and electronics, refers to the state where the number of minority carriers generated is small compared to the majority carriers of the material. In this condition minority carrier recombination rates are proportional to the number of carriers squared.

Is BJT a minority carrier?

By design, most of the BJT collector current is due to the flow of charge carriers (electrons or holes) injected from a heavily doped emitter into the base where they are minority carriers that diffuse toward the collector, and so BJTs are classified as minority-carrier devices.

What is minority carrier concentration?

The more abundant charge carriers are the majority carriers; the less abundant are the minority carriers. The equilibrium carrier concentration can be increased through doping. The total number of carriers in the conduction and valence band is called the equilibrium carrier concentration.

What is p-type and n-type carriers?

In a p-type semiconductor, the majority carriers are holes, and the minority carriers are electrons. In the n-type semiconductor, electrons are majority carriers, and holes are minority carriers. In the p-type semiconductor, the acceptor energy level is close to the valence band and away from the conduction band.

What is range of carrier life time?

What is the range of the carrier lifetime? Explanation: Carrier lifetime is defined as the existence of any carrier for τ seconds. Carrier lifetime ranges from nanoseconds to hundreds of microseconds. 2.

What is the minority carrier lifetime in silicon wafer?

The Minority Carrier Lifetime in Silicon Wafer. The minority carrier “lifetime” (τ) measures how long a carrier is likely to stay around for before recombining and is one of the most important parameters for the characterization of semiconductor wafers used in the preparation of power electronic devices and photovoltaic solar cells.

What is the meaning of a minority charge carrier device?

BJT is a minority charge carrier device. Could someone explain it? As we know, BJT is Biploar junction transistor. It means both holes & electrons are responsible for conduction of the device.

How to measure the minority-carrier lifetimes of III-V compound semiconductors?

The minority-carrier lifetimes of III-V compound semiconductors are most easily characterized by time-resolved photoluminescence. This is a quick and contactless technique which directly measures the excess minority-carrier carrier density. By using a focused laser beam as the excitation source, the required sample area may be very small.

What is the best way to measure minority-carrier lifetime?

Two recent textbooks have provided descriptions of a variety of minority-carrier lifetime measurement [ 1,2] techniques. The measurement of minority-carrier lifetime in compound semiconductors is usually performed by a time-resolved photoluminescence technique [1] (TRPL).