Semiconductor vs Metal
Metals are known to human kind for a very long time. There are evidences to prove about metal usage back in 6000 BC. Gold and copper were the first metals to be discovered. These were used to make tools, jewelry, statues, etc. Since then for a longer period only few other metals (17) were discovered. Now we are familiar with 86 different types of metals. Metals are very important because of their unique characteristics. Usually metals are hard and strong (there are exceptions to this such as sodium. Sodium can be cut by a knife). Mercury is a metal, which is in the liquid state. Besides mercury, all the other metals are found in the solid state, and it is hard to break them or change their shape compared to other non-metal elements. Metals have a shiny appearance. Most of them have a silvery shine (except gold and copper). Since some metals are very reactive with the atmospheric gases like oxygen, they tend to get dull colors over time. This is mainly due to the formation of metal oxide layers. On the other hand, metals like gold and platinum are very stable and un-reactive. Metals are Malleable and ductile, which allows them to be used for making certain tools. Metals are atoms, which can form cations by removing electrons. So they are electro-positive. The type of bond forms between metal atoms is called metallic bonding. Metals release electrons in their outer shells and these electrons are dispersed between metal cations. Therefore, they are known as a sea of delocalized electrons. The electrostatic interactions between the electrons and cations are called metallic bonding. The electrons can move; therefore, metals have the ability to conduct electricity. Also, they are good thermal conductors. Because of the metallic bonding metals have an ordered structure. High melting points and boiling points of metals are also due to these strong metallic bonding. Moreover, metals have a higher density than water. Elements in group IA, IIA are light metals. They have some variations from the above described general features of metal.
Conductors are materials with high electric conductivity. Insulators are materials that do not conduct electricity. Semiconductors are the materials in between conductors and insulators. So its electrical conductivity is in between that of conductors and insulators. A semiconductor can be an element or a compound. Silicon is a most commonly used element as a semiconductor material. Germanium is also another example for this. The conductivity of this pure element is changed by adding various quantities of impurities. These are known as dopants and addition of these is known as doping. Mostly used dopants for silicon are boron or phosphorus. Doped semiconductors are also known as extrinsic. Other than elements, organic compounds can also be act as semiconductors. The mechanism of electricity conducting in semiconductors is different. Some of the semiconductors carry electricity via electrons (N type) while some carry electricity via positively charged holes (p type). Semiconductors are widely used in electric equipment like computers, radios, telephones, etc. they are also included in solar cells, transistors, diodes, etc.
What is the difference between Semiconductor and Metal?
• Metals are conductors and therefore they carry high amount of electricity. Semiconductors have less electrical conductivity than metals.
• In metals electrons carry out the current. But in semiconductors, current is carried out by the flow of electrons of positively charged holes.