An LED (Light Emitting Diode) is constructed | vedclass

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(A) The wavelength $\lambda$ of the emitted light is given by the relation: $\lambda = \frac{hc}{E_g}$ where $h = 6.63 	imes 10^{-34} \, J \cdot s$ i

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$650\, nm$

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(A) The wavelength $\lambda$ of the emitted light is given by the relation: $\lambda = \frac{hc}{E_g}$ where $h = 6.63 	imes 10^{-34} \, J \cdot s$ is Planck's constant,$c = 3 	imes 10^8 \, m/s$ is the speed of light,and $E_g$ is the energy gap. Given $E_g = 1.9 \, eV = 1.9 	imes 1.6 	imes 10^{-19} \, J$. Substituting the values: $\lambda = \frac{6.63 	imes 10^{-34} 	imes 3 	imes 10^8}{1.9 	imes 1.6 	imes 10^{-19}} \, m$ $\lambda \approx \frac{19.89 	imes 10^{-26}}{3.04 	imes 10^{-19}} \, m$ $\lambda \approx 6.54 	imes 10^{-7} \, m$ $\lambda \approx 654 	imes 10^{-9} \, m = 654 \, nm$. Rounding to the nearest provided option,the wavelength is $650 \, nm$.

An $LED$ (Light Emitting Diode) is constructed from a $p-n$ junction based on a certain $Ga-As-P$ semiconducting material whose energy gap is $1.9\, eV$. What is the wavelength of the emitted light?

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