What is Semiconductor? Working, Types, Features, & Uses

Hello, readers welcome to the new post. In this post, we will discuss What is Semiconductor. Semiconductors are material that has conductivity between conductors and non-conductors. The semiconductor can also come in compound forms like gallium arsenide, or pure components like germanium or silicon. Gallium arsenide, germanium, and silicon are commonly used semiconductors. Silicon is used in electronic circuit manufacturing and gallium arsenide is part of solar cells and laser diodes. let’s get started with What is Semiconductor?

Table of Contents

Types of Semiconductors

Semiconductors has two main types on the base of components that are added silicon, this process is called doping. These impurities are added to crystalline silicon to vary the featues of the completed semiconductor material. The N-type semiconductor comes with one or more impurities based on pentavalent atoms. Such as phosphorous, arsenic, and bismuth.

The P-type semiconductor material has dopants with 5 electrons in the valence layer. Phosphorus is used in the valance layer with arsenic, or antimony.

Difference between N-type and P-type semiconductors

The N-type semiconductor has curent in the form of negatively charged electrons like conduction of current in write. The P-type semiconductor carries curent due to holes. The hole has a positive electric charge, equal and opposite to the charge of an electron.

For semiconductor material flow of holes exists in the reverse direction to the flow of electrons. Silicon is normally used for creating mostly integrated circuits. Commonly semiconductor compounds are gallium arsenide, indium antimonide, and oxides of mostly metals.

Properties of Semiconductors

Semiconductors cause current in required conditions and features. These featues make it good to flow curent in a controlled fashion. Contrary to conductors charge carriers in semiconductors are excited due to external energy. it results specific number of valence electrons crossing the energy gap and moving in the conduction band leaving an equal number of unoccupied energy states that are called holes.

Semiconductors work like insulators at 0 kelvin. On increasing temperatue, they work as conductors.
Due to electrical features, semiconductors can be modified with doping to make semiconductor devices best for energy transformation switches and amplifiers.
it has fewer energy losses.
Semiconductors are small in size and have less weight.
They have high resistivity as compared to conductors but less thatn insulators.
The resistance of semiconductor materials reduces with increases in temperature and vice versa.

Why Does the Resistivity of Semiconductors Decrease with Temperature?

The difference in resistivity between conductors and semiconductors is due to differences in charge carrier density. The resistivity of the semiconductor reduces with temperature due to the number of charges that carry increase fastly with the rise in temperatue. make fractional chance such as temperature coefficient negative.

Difference between Intrinsic and Extrinsic Semiconductors

Intrinsic Semiconductor

It is a pure semiconductor and the density of electrons is equal to the hole density
The density of electrons is equal to holes density.
it has low electrical conductivity
it is based on the temperature
it does not have impurities.

Extrinsic Semiconductor

It is an impure semiconductor
The density of electrons is not equal to the hole density
it has high electrical conductivity.
it is based on temperature and impurities added
It has trivalent and pentavalent impurity

Energy bands and electrical conduction

A semiconductor is defined as the base of electric conductive featues that is between conductor and insulator. The difference between these materials is defined in terms of the quantum states of electrons each can have zero or no electrons. These states are related with the electronic band structure of material
Electrical conductive increases due to the existence of electrons in states that are delocalized but for transporting electrons state must be partially filled. Comes with electrons only part of the time.

If the state is covered with electrons then it is inert blocking the flow of electrons. The energy of these quantum states is important due to the state is partially filled only if its energy is close to the Fermi level.
High conduction in the material is from having many partially filled states and much state delocalization. Metals are good electrical conductors and come with partially filed states with energies close to the Fermi level.
Insulators come with partially filled states their Fermi levels exist in band gaps with some energy states to occupy.
With that insulator can created to operate through increased temperature, heating over the energy gap to promote some electrons about the band gap such as a partially filled state in both bands of states below the band gap and band of states over the band gap. The semiconductors come with a band gap that is less thatn the insulator and room temperatue, important number of electrons are excited to cross the band gap.
The pure semiconductor is not useful since it is not a good conductor not a good insulator. But one feature of semiconductors is that conductivity can increase and regulate with doping with impurity and gating with electrical fields.