Explore BrainMass
Share

Valance Bands & Energy to Produce and Electron Hole Pair

This content was STOLEN from BrainMass.com - View the original, and get the already-completed solution here!

3. A material has an effectively full valence band and an empty conduction band. Explain why that if these two bands overlap the material behaves as a metal and if they are separated by a few electron volts in energy the material is an insulator.

4. Calculate the minimum energy a photon must have to produce an electron hole pair in an extrinsic semiconductor of band gap 1.0 electron volts.

© BrainMass Inc. brainmass.com October 24, 2018, 8:18 pm ad1c9bdddf
https://brainmass.com/chemistry/general-chemistry/valance-bands-energy-produce-electron-hole-pair-93044

Solution Preview

Please see the attached file.

3. A material has an effectively full valence band and an empty conduction band. Explain why that if these two bands overlap the material behaves as a metal and if they are separated by a few electron volts in energy the material is an insulator.
Answer:

Explanation for why if these two bands overlap the material behaves as a metal:

When electron is in valence band, it can not contribute to the conduction process. But when it gets excited to conduction band, it contributes in the conduction process.

Consider the situation when completely filled valence band and an empty conduction band overlap. If there are N number of atoms in the metal, then there are N energy levels in a valence band and N energy states in empty conduction band. The ...

Solution Summary

Word file explains the effects of overlapping valence and conduction bands and calculates the minimum energy a photon must have for an electron hole pair in a semiconductor.

$2.19
See Also This Related BrainMass Solution

PN Junction - explanation and uses

Describe how a pn junction works and how it is used in diodes, LEDs and lasers.

View Full Posting Details