Semiconductors are materials that conduct electricity under certain conditions, lying between conductors and insulators. They are widely used in electronics like microprocessors, transistors, and any computerized or radio-using devices. Semiconductors are made of covalently bonded atoms that share electrons. When an electron leaves its atom, it creates an "hole" that can be filled by another electron, generating electron-hole pairs that allow electric current to flow through the semiconductor material. The most common semiconductor materials are silicon and germanium. Semiconductors can be classified as intrinsic, with virtually no impurities, or extrinsic, which are doped with impurities to have extra electrons or holes that enhance conductivity.

1. What are they
Semiconductors
By Jaime Turowiecki
17.325.341

2. Semiconductors have been widely in our society. You can find
many places semiconductors , microprocessors and also in
transistors or anything that is computerized or uses radio waves ,
because these depend on semiconductors. Nowadays , many
semiconductor chips and transistors are made with silicon , and in
fact can be considered that the silicone is the core of any
electronic device . In electronic semiconductors they are very
important , since many components are produced with them.
Now , you can define the semiconductors how the materials
that behave as conductors only under certain circumstances.
There are good drivers, but they are not insulators, which is why
we are said to lie somewhere in the middle between them.
Semiconductors

3. Theory of Semiconductors
Any atom has the
same number of
protons in the
nucleus that
electrons rotate in
orbits around the
nucleus . The
positively charged
protons are canceled
by the negative
electrons , so the
atom in its normal
state, it hasn’t
electrical charge.
But all atoms aren´t equal. Each element of the periodic table has
different atoms , but all consist of the same particles : protons,
neutrons and electrons . They differ only in the number of them .
Electron
Orbit
Proton
Electron
Nucleus

4. Theory of Semiconductors
Electrons are particles that really matter to study electrical conduction.
The electric current is a movement of electrons. If we are able to move
electrons from the atoms of a material , we will generate electric
current through it. This equipment will become conductor.
Only the last layer of electrons
, called valence electrons are
used. These are what we use
to make them leave the
atom , to turn to another and
cause electric current through
the material
Conduction band
Bandgap
Band of Valencia
Electron
They can be found in three
different types of bands
A semiconductor is characterized by a band gap between the
conduction and valence , but not very wide

5. Semiconductors
All semiconductors are materials that are covalently bonded
atoms . Share electrons in its last layer 2 by 2. One of these
shared electrons between two atom through a covalent bond,
which will have to start
When an electron leaves the atom
breaks the covalent attachment of
pairs of electrons and leave an
empty hole . This gap can be
filled , quite the deal , another
electron that had left him another
nearby atom. So they are
generating holes and these holes
are populated by other electrons
from other atoms. This is how the
current flows through the
semiconductor , electron-hole pairs

6. Semiconductors
Intrinsic Semiconductors Extrisic Semiconductors
The two materials most commonly used to manufacture
semiconductors are germanium and silicon. However , a material
purify hundred percent , requires very expensive process , which
makes the materials used contain many impurities. For the
amount of impurities that have , can be classified into intrinsic
and extrinsic
They are the ones who have
virtually no impurities.
an impurity atom for every 10
to 11
They are used as temperature
-sensitive elements
Are those with an impurity
atom for every 10 to 7 atoms
semiconductor
usually they take 3 to 5
valence electrons.
They can be divided into two
types : Type N and P type
doped N type 5 valence
electrons. P type doped 3
valence electrons

7. Thank You for
your attention