Q. The energy of radiation emitted by LED is
A) Greater than the band gap of the semiconductor used
B) Always less than the band gap of the semiconductor used
C) Always equal to the band gap of the semiconductor used
D) Equal to or less than the band gap of the semiconductor used
Explanation
(d) The energy emitted by LED is equal to or less than the band gap, because one has also two other energy bands due to the acceptor and donor levels just above $E_{V}$ and just below $E_{C}$
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Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.