Summary of HC Verma Solutions Part 2 Chapter 45: Semiconductors And Semiconductor Devices
FAQs on HC Verma Solutions Class 12 Chapter 45 - Semiconductors and Semiconductor Devices
1. What are semiconducting devices ?
Semiconductor device, electronic circuit component made from a material that is neither a good conductor nor a good insulator (hence semiconductor). Such devices have found wide applications because of their compactness, reliability, and low cost.
2. What materials are used in semiconductors?
The most used semiconductor materials are silicon, germanium, and gallium arsenide. Of the three, germanium was one of the earliest semiconductors materials used. Germanium has four valence electrons, which are electrons located on the outer shell of the atom.
3. Why are semiconductors used in electronics?
Semiconductors are used in many electrical devices because we can control the flow of electrons in this material, for example, with a controlling current. Semiconductors are also used for other special properties. In fact, a solar cell is made of semiconductors which are sensitive to light energy.
4. What are pentavalent elements?
Pentavalent elements are those elements which have five electrons in their outer shell. Since electrons are negative charge carriers, the resultant material is called an n-type (or negative type) semiconductor. The pentavalent impurity that is added is called a ‘dopant’ and the process of addition is called ‘doping’.
5. Why is p-type semiconductor positively charged?
Because an acceptor dontes excess holes, which are considered to be positively charged, a semiconductor that has been doped with an acceptor is called a p-type semiconductor; “p” stands for positive. Notice that the material as a whole remains electrically neutral.