Direct Energy, 2018a

136 6.8 Problems
6.8 Problems
6.1. Rank the materials from smallest energy gap to largest energy gap:
• Indium arsenide, InAs
• Aluminum arsenide, AlAs
• Gallium arsenide, GaAs
6.2. The energy level diagram for a silicon pn junction is shown in the
gure below. Part of the device is doped with Ga atoms, and part of
the device is doped with As atoms. Label the following:
• The valence band
• The conduction band
• The energy gap
• The n-type region
• The p-type region
• The depletion layer
• The part of the device doped with Ga
• The part of the device doped with As
2
Energy in eV
2.5
3
E f
3.5
4
Position