Q. A $P$-type semiconductor has acceptor levels $57\ meV$ above the valence band. The maximum wavelength of light required to create a hole is (Planck’s constant $h = 6.6 \times 10^{- 34}J$-$s$)
A) $57\ \mathring{\mathrm{A}}$
B) $57 \times 10^{- 3}\ \mathring{\mathrm{A}}$
C) 217100 $\mathring{\mathrm{A}}$
D) $11.61 \times 10^{- 33}\ \mathring{\mathrm{A}}$
Explanation
(c) $E = \frac{hc}{\lambda} \Rightarrow \lambda = \frac{hc}{E} = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{57 \times 10^{- 3} \times 1.6 \times 10^{- 19}} = 217100\mathring{\mathrm{A}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.