An LED is constructed from a p - n junction diode using GaAsP. The energy gap is 1.9 ~eV . The wavelength of the light emitted will be equal to

Step-by-step solution

The energy of the emitted photon is given by the energy gap E_g of the semiconductor material. E_g = 1.9 eV = 1.9 1.6 10⁻¹⁹ J = 3.04 10⁻¹⁹ J The relationship between the energy of a photon and its wavelength is given by E = hc , where h = 6.63 10⁻³⁴ J s and c = 3 10^8 m/s . Rearranging for wavelength: = hc E_g = 6.63 10⁻³⁴ 3 10^8 3.04 10⁻¹⁹ = 19.89 10⁻²⁶ 3.04 10⁻¹⁹ 6.54 10⁻⁷ m Converting to nanometers: = 654 10⁻⁹ m = 654 nm Answer: 654 ~nm