Physics · Semiconductors, semiconductor diode: I-V characteristics in forward and reverse bias, diode as a rectifier
The energy band diagrams for three semiconductor sample of silicon are shown. It
The energy band diagrams for three semiconductor sample of silicon are shown. It follows that.
- A. Sample X is undoped while samples Y and Z have been doped with a third group and a fifth group impurity respectively
- B. Sample X is undoped while both samples Y and Z have been doped with a fifth group impurity
- C. Sample X has been doped with equal amounts of third and fifth group impurities while samples \( Y \) and \( z \) are undoped
- D. Sample X is undoped while samples Y and Z have been doped with a fifth group and a third group impurity respectively
Step-by-step solution
In intrinsic (undoped) silicon, the Fermi level lies near the middle of the band gap. Doping with a third-group impurity (acceptor) shifts the Fermi level toward the valence band, while doping with a fifth-group impurity (donor) shifts it toward the conduction band. The band diagrams typically show X with Fermi level at mid-gap (undoped), Y with Fermi level near the valence band (p-type, third group), and Z with Fermi level near the conduction band (n-type, fifth group).