Question

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. $57\stackrel{\circ }{A}$
• B. $57\times {10}^{-3}\stackrel{\circ }{A}$
• C. $217100\stackrel{\circ }{A}$
• D. $11.61\times {10}^{-33}\stackrel{\circ }{A}$

Answer 1

The correct option is C $217100\stackrel{\circ }{A}$

$E=\frac{hc}{\lambda }\Rightarrow \lambda =\frac{hc}{E}=\frac{6.6\times {10}^{-34}\times 3\times {10}^8}{57\times {10}^{-3}\times 1.6\times {10}^{-19}}=217100\stackrel{\circ }{A}$.