Concept used

In a semiconductor, light can create a charge carrier if the photon energy is at least equal to the required excitation energy.

For maximum wavelength, the photon must have minimum required energy: $E = \frac{hc}{\lambda_{\max}}$

Given data

$E = 6\ \text{eV}$ $hc = 1242\ \text{eV nm}$

Calculate maximum wavelength

$\lambda_{\max} = \frac{hc}{E} = \frac{1242}{6}\ \text{nm}$

$\lambda_{\max} = 207\ \text{nm}$

Match with options

• A: $407\ \text{nm}$
• B: $103.5\ \text{nm}$
• C: $414\ \text{nm}$
• D: $207\ \text{nm}$

Hence, the correct option is: $\boxed{\text{D: }207\ \text{nm}}$

Comparison with stored answer

Stored correct answer = D, which matches our result.