What is minority carrier injection?
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. Each semiconductor material contains two types of freely moving charges: electrons (negative charges) and holes (positive charges).
What is meant by carrier injection?
Definition. carrier injection. the process of introducing charge carriers from one region within semiconductor device to another (e.g. in a forward-biased p-n junction electrons are injected to the p-type region and holes are injected to the n-type region).
What is majority and minority carriers?
The majority charge carriers carry most of the electric charge or electric current in the semiconductor. Hence, majority charge carriers are mainly responsible for electric current flow in the semiconductor. The charge carriers that are present in small quantity are called minority charge carriers.
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.
What are the minority carriers in NPN transistor?
EXPLANATION: In an NPN transistor, holes are the minority carriers and free electrons are the majority carriers.
Which carrier is the minority carrier?
semiconductor devices …p side; these are termed minority carriers. On the n side the electrons are the majority carriers, while the holes are the minority carriers. Near the junction is a region having no free-charge carriers. This region, called the depletion layer, behaves as an insulator.
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.
What is the difference between low level injection and high level injection?
The assumption of low-level injection can be made regarding an n-type semiconductor, which affects the equations in the following way: In comparison, a semiconductor in high injection means that the number of generated carriers is large compared to the background doping density of the material.
Do low level injection conditions prevail?
Yes, low level injection conditions prevail inside the illuminated bar because the maximum value of excess carrier concentration is 10-3ND which is much less than the equilibrium concentration of majority carriers, i.e. n = n0 + n n.
What are the majority carriers in PNP transistor?
Detailed Solution The emitter provides the majority charge carriers, which are holes. Hence in pnp transistors, majority carriers are holes.
How do you know if type is N or p?
The easiest would be judging form the periodic table. If the dopant has more electrons in the outer shell than the semiconductor material, it’s going to be n-type, and with less electrons in the outer shell, it’s p-type.