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INSULATOR CONDUCTOR and SEMICONDUCTOR.pptx
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- 2. Every atom wantsstability, so it gains, loses or shares to complete its outermost shell so it becomes stable
- 3. Insulator a material thatblock or retard the flow of electron. Plastic Rubber Glass
- 4. Insulator Atomic Structure CompleteValance Shell, 5-7 valance electron in its outermost Shell.
- 5. Conductor a material inwhich electrical charge carriers, usually electrons, move easily from atom to atom with the application of voltage or current. Aluminum Copper Graphite
- 6. Conductor Atomic Structure Incompleteoutermost shell. 1-3 Valance Electron in it’s outermost shell.
- 7. Semiconductor a material thatis neither a good conductor nor a good insulator Silicon germanium P-type / N-type
- 8. Semiconductor Atomic Structure Incompleteoutermost shell. 4 Valance Electron in it’s outermost shell.
- 9. Energy Band an enormouslylarge number of energy levels closely spaced in a very small energy range constitute energy band. • Valance Band The highest energy band filled with valence electrons is called valence band. • conduction band The lowest unfiled allowed energy band next to valence band is called conduction band.
- 10. • energy gapor band gap or Forbidden Band The gap between top of valence band and bottom of conduction band in which no allowed energy levels for electrons can exist is called energy gap or band gap. A position in which conduction band and valance band over lap each other is called overlap region, in this region electron jump from valance band to conduction band where conduction process is been occurred.
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- 12. Why gap bandis called Forbidden Energy Band? the electrons do not stay in forbidden gap as there is no energy state in this region.