Question

In GaAsP, if $E_g = 1.9 \, \text{eV}$, the emission wavelength is:

• A. 7538 Å
• B. 6538 Å
• C. 6533 Å
• D. 6133 Å

Hint:

Photon energy and wavelength are related by $E = \dfrac{hc}{\lambda}$. Use the 12400 rule for quick estimates.

Answer 1

The Correct Option is C

Step 1: Formula.
$\lambda = \dfrac{12400}{E_g (\text{eV})}$ Å.

Step 2: Substitute.
$\lambda = \dfrac{12400}{1.9} \approx 6526$ Å, which is closest to 6533 Å.

Final Answer: \[ \boxed{6533 \, \text{Å}} \]