Question

Find the maximum wavelength of the light that will excite an electron in the valence band of diamond to the conduction band. The energy gap is $ 5.5\, eV $

• A. 225 nm
• B. 315 nm
• C. 352 nm
• D. 412 nm

Answer 1

Answer: (A)

Given, $E=5.5\,eV =5.5\times1.6\times10^{-19}\,J $
To find $\lambda_{max}=$ ?
$E=\frac{hc}{\lambda}=\frac{6.6\times10^{-34}\times3\times10^{8}}{\lambda}$
$5.5\times1.6\times10^{-19}=\frac{6.6\times10^{-34}\times3\times10^{8}}{\lambda}$
$\lambda=\frac{6.6\times10^{-34}\times3\times10^{8}}{5.5\times1.6\times10^{-19}}$
$\lambda=225\times10^{-9}\,m$
$=225\,nm$