Doping:
The conductivity of silicon and germenium can be drastically increased by the controlled addition of impurities to the intrinsic (pure) semiconductor material. This process, called doping, increases the number of current carriers (electrons or holes).
N Type Semiconductor:
To increase the number of conduction band electrons , pentavalent impurity atoms like arsenic (As), phosphorus (P), bismith(Bi) and antimony (Sb) are added.
Each pentavalent atom leaves an extra free conduction electron after combining with the silicon atom forming covalent bond.As pentavalent atom gives an electron so called donar atom.
The number of conduction electrons can be controled by the impurities ato added to silicon.
Most of current carriers are electron,silicon doped with pentavalent atoms is an n-type semiconductor material.The electrons are called majority carriers.There are also some holes when electrons are paired when thermally processed.These holes are called minority carriers.
Popular Posts
-
An ammeter , which is used for measuring current, offers a low level resistance (ideally 0) & must be connected in series with the ci...
-
The 555 Timer is an integrated circuit (chip) implementing a variety of timer and multivibrator applications. The IC was designed and inve... -
The two-port network has a pair of input terminals, shown as PQ in Figure below, & a pair of output terminals, shown as RS in the dia... -
All analogue electrical indicating instruments need 3 essential devices these devices are briefly discussed below: 1- A deflecting or op...
-
As you know the primary gain parameter of a standard bipolar transistor is beta. Beta describes the ratio of the current flow through the b... -
Below is the List of Advanced Electronics formulas: Comlex numbers formulas LR-C network formula LR-CR formulas Advanced Electronics ... -
The Electrons and holes performs a chaotic random thermal motion. The average kinetic energy of thermal motion per one electron is given... -
The BCD counters are not binary counters. The Binary counters divide by 2 at each stage, and their outputs run from 0 to (2 n - 1), wher...
-
Figure below demonstrates the significance of correctly matching input and output impedances between stages of the circuit. The AC signal... -
1428. The Miller oscillator is the crystal equivalent of a Hartley oscillator in which no mutual inductance exists between the plate-to c...
1 comments:
It's funny that somehow, we always get taught about semiconductor doping without learning much about who stated the process. Who was the first one to figure out that adding impurities to the metal increased its conductivity?
I would like to know this, just for the sake of trivia. However, in the long run, all we need to know is the process behind the creation of the materials that are used to build the devices that are the backbone of most industries nowadays.
Post a Comment