the impurity add here is 1 atom of per million atoms of semiconductor.......
The main reason semiconductor materials are so useful is that the behavior of a semiconductor can be easily manipulated by the addition of impurities, known as doping. Semiconductor conductivity can be controlled by introduction of an electric or magnetic field, by exposure to light or heat, or by mechanical deformation of a doped mono-crystalline grid; thus, semiconductors can make excellent sensors. Current conduction in a semiconductor occurs via mobile or "free"electrons and holes. collectively known as charge carriers. Doping a semiconductor such as silicon with a small amount of impurity atoms, such as phosphorus or boron. greatly increases the number of free electrons or holes within the semiconductor. It can be make in very small size and the electronics device are small in size that why the semiconductors are used in electronic devices. The above explains HOW semi conductors work. The reason for WHY they are used is, what's the alternative? The only alternative is thermionic valves (tubes). Tubes fell out of favour for many reasons. They run hot Made of glass and delicate, Heavy Large Consume lots of power Need high voltages. Semi conductors are the opposite of all of these.
The thickness of the depletion region or depletion layer (and there are other terms) varies as the design of the semiconductor. The layers in a semiconductor are "grown" (usually by deposition), and this can be controlled. The typical depletion region thickness in an "average" junction diode is about a micron, or 10-6 meters. Junction "construction" presents major engineering considerations to those who design and make semiconductors as there are many different kinds. A link is provided to the section on the width of depletion regions in the Wikipedia article on that topic.
The material may be influenced to conduct electricity or not. So it does not always conduct, sometimes partially, sometimes not at all - hence the prefix semi (= half)
semiconductors are silicon and germanium. they are like metals but their highest occupied electron shells/orbitals do not overlap. they require a little energy to exite electrons into the conduction band. Small amounts of group 3 or 5 elements can be changed to dramatically alter conductivity. the structure of carbon allotropes, such as diamond and graphite, do not allow this. Diamond is a covalent network with no free electrons. Graphite is layers of hexagonal carbon networks with electrons allowed to flow in one directing only. Adding these metal impurities, if it can be done easily, will not have the same effect
That all depends on the deal you can make. There is no set amount.
silicon is intrinsic semiconductor until we add some impurities in it. the impurities are either of group 3 called acceptors which make p type or of group 5 called donors which make n type semiconductor.
at higher values of temperature the intrinsic carrier concentration become comparable to or greater than doping concentration in extrinsic semiconductors. thus majority and minority carrier concentration increases with increase in temperature and it behaves like intrinsic semiconductor.
intrinsic semiconductor is an un-doped semiconductor, in which there is no impurities added where as extrinsic semiconductor is a doped semiconductor, which has impurities in it. Doping is a process, involving adding dopant atoms to the intrinsic semiconductor, there by gives different electrical characteristics
A semiconductor slice is used to make integrated circuits or ICs. It is also known as a semiconductor wafer or a semiconductor substrate.
Semi-metals, also known as metalloids, are typically made through a process called doping. This involves adding small amounts of impurities to a pure semiconductor material, such as silicon or germanium. The impurities alter the electronic properties of the material, making it exhibit characteristics of both metals and non-metals.
Donor impurities in silicon are atoms of elements that have one more electron than silicon, such as phosphorus or arsenic. These impurities are used to make silicon into an n-type semiconductor, which means they increase the number of free electrons in the material, making it conductive.
You could replace As in GaAs with elements like Zn, Be, or Mg to create p-type semiconductor materials. These elements will introduce acceptor impurities in the GaAs crystal structure, resulting in a deficiency of electrons and the formation of positively charged holes, leading to p-type doping.
* silicon * germanium * gallium arsenide * etc.
There are different types of sugar: Intrinsic sugar - naturally occurs in the structure of the foods in which they are found e.g. fruit & vegetables. Extrinsic sugar - is sugar that has been added or is freely available in foods and can easily damage teeth, e.g. most sugar in processed foods is extrinsic. It's not important whether sugar is 'natural' or not, e.g. sugar in an apple is intrinsic, but if processed to make juice or stewed it then becomes extrinsic. Sugar in milk (lactose) is extrinsic, but compared to non-milk extrinsic sugar it's relatively harmless. In a nutshell, non-milk extrinsic sugars are the ones to cut down on.
There are different types of sugar: Intrinsic sugar - naturally occurs in the structure of the foods in which they are found e.g. fruit & vegetables. Extrinsic sugar - is sugar that has been added or is freely available in foods and can easily damage teeth, e.g. most sugar in processed foods is extrinsic. It's not important whether sugar is 'natural' or not, e.g. sugar in an apple is intrinsic, but if processed to make juice or stewed it then becomes extrinsic. Sugar in milk (lactose) is extrinsic, but compared to non-milk extrinsic sugar it's relatively harmless. In a nutshell, non-milk extrinsic sugars are the ones to cut down on.
Arsenic is not a semiconductor by itself, but it is commonly used as a dopant in semiconductor materials like silicon to alter their electrical properties. Arsenic increases the number of available charge carriers in the material, which can make it conduct electricity more effectively.
The main reason semiconductor materials are so useful is that the behavior of a semiconductor can be easily manipulated by the addition of impurities, known as doping. Semiconductor conductivity can be controlled by introduction of an electric or magnetic field, by exposure to light or heat, or by mechanical deformation of a doped mono-crystalline grid; thus, semiconductors can make excellent sensors. Current conduction in a semiconductor occurs via mobile or "free"electrons and holes. collectively known as charge carriers. Doping a semiconductor such as silicon with a small amount of impurity atoms, such as phosphorus or boron. greatly increases the number of free electrons or holes within the semiconductor. It can be make in very small size and the electronics device are small in size that why the semiconductors are used in electronic devices. The above explains HOW semi conductors work. The reason for WHY they are used is, what's the alternative? The only alternative is thermionic valves (tubes). Tubes fell out of favour for many reasons. They run hot Made of glass and delicate, Heavy Large Consume lots of power Need high voltages. Semi conductors are the opposite of all of these.