Energy Bands in Solids

PHY-118 · Semester I · Physics

Sandboxintermediate12 minAvailable

Energy bandsConductor · Semiconductor · Insulator

Semiconductor · Eg = 1.10 eV

BandsValenceConductionGap

Material

Semiconductor

Band gap

1.10eV

Temperature

300K

Conduction

Negligible

How to play

Objective

See how atoms packed into a crystal smear their discrete energy levels into bands, and how the gap between the valence and conduction bands decides metal, insulator or semiconductor.

The idea

Bring atoms together and their energy levels split into bands. If the bands touch, electrons flow easily - a metal. If a wide gap separates them, it is an insulator. Semiconductors sit in between.

Try this

1Cram more atoms in and watch levels smear into bands.
2Toggle the lattice spacing and watch the band gap change.
3Compare metal, semiconductor and insulator cases.
4Look for the gap that blocks or lets conduction happen.

Watch for

Individual levels become bands as atoms crowd together.
The band gap decides whether electrons can jump to conduct.
Metals have a half-filled band; insulators have a wide gap.
Doping and heat can promote electrons across a small gap.