Question

The direct-bandgap semiconductors InGaN, GaAs, and InGaAsP are 3.06, 1.24, and 0.8eV, respectively.

a) What would be the typical emission wavelengths if each of them were used to make a semiconductor laser?

Answer 1

The typical emission wavelengths for the direct-bandgap semiconductors InGaN, GaAs, and InGaAsP when used in semiconductor lasers are approximately 405 nm, 1000 nm, and 1550 nm, respectively, calculated by relating the bandgap energy to the wavelength using Planck's constant and the speed of light.

Step-by-step explanation:

The student's question pertains to the typical emission wavelengths for the direct-bandgap semiconductors InGaN, GaAs, and InGaAsP, with bandgaps of 3.06, 1.24, and 0.8eV, respectively. To calculate the emission wavelengths for these semiconductors when used in a semiconductor laser, we can apply the relationship between the bandgap energy (E, in electron volts) and the wavelength (λ, in meters) using the equation E = (hc) / λ, where h is Planck's constant (6.626 x 10-34 J∙s) and c is the speed of light in a vacuum (3 x 108 m/s).

For InGaN (3.06 eV): λ = (6.626 x 10-34 J∙s)(3 x 108 m/s) / (3.06 eV)(1.602 x 10-19 J/eV) ≈ 405 nm

For GaAs (1.24 eV): λ = (6.626 x 10-34 J∙s)(3 x 108 m/s) / (1.24 eV)(1.602 x 10-19 J/eV) ≈ 1000 nm

For InGaAsP (0.8 eV): λ = (6.626 x 10-34 J∙s)(3 x 108 m/s) / (0.8 eV)(1.602 x 10-19 J/eV) ≈ 1550 nm