Introduction to Semiconductors and Devices Seminar Topic:
This paper discussed about the atomic structure of semiconductors and its importance, also discussed about the concepts of energy bands and energy bands gaps.
Overview:
Based on the ability of conducting electricity, materials are classified into conductors, semiconductors and insulators. Semiconductors have ability to carry conductivity between the insulators and the conductors. For easy understanding of semiconductor topic there is a need to apply modern physics to solid materials. The foundation of electronic devices is formed with the devices made out of semiconductors. Semiconductors resistivity can change by an external electrical field. In semiconductors, in the electronic structure of the material current can be carried either by the flow of positively charged “holes” or by the flow of electrons.
Semiconductors are classified into extrinsic and intrinsic semiconductors. The semiconductors in its natural form are termed as intrinsic semiconductors. The process of changing an intrinsic semiconductor to an extrinsic semiconductor is known as semiconductor doping. In this process impurity atoms got introduced to an intrinsic semiconductor.
Impurity atoms changes semiconductor’s electron and hole concentrations, also acts as either donors or acceptors to the intrinsic semiconductor. Based on the effect on intrinsic semiconductors, impurity atoms are classified into donor or acceptor atoms. Donor impurity atoms have more valence electrons and Acceptor impurity atoms have less valence electrons than the atoms they replace in the intrinsic semiconductor lattice. When a semiconductor has been doped by introducing a doping agent and having different electrical properties compared to that of intrinsic semiconductor is termed as an external semiconductor. N-type and P-type are two types of extrinsic semiconductors.
Conclusions:
Most of the electronic devices are using semiconductors. All electronic devices like Computer, TV, radio, DVD player are worked only on dc power supply rather than ac power supply. So, there is a need of diodes to convert the ac to dc power. Now-a-days, semiconductors play a vital role in all the electronic devices.
Download NIT IT Final Year Seminar Report on Semiconductors and Devices for IT Students .