LED is constructed from Ga-As-P semiconducting material. The energy gap of this LED is 1.9 eV. Calculate the wavelength of light emitted and its colour.
[h = 6.63 $\times$ 10$-$34 Js and c = 3 $\times$ 108 ms$-$1]
Solution
We know that $E = {{hc} \over \lambda }$<br><br>$\lambda = {{hc} \over E} \Rightarrow {{1240(in\,eV)} \over {E(in\,eV)}}$<br><br>$\lambda = {{1240} \over {1.9}}$<br><br>= 652.63 nm $\approx$ 654 nm<br><br>Wavelength of red light is 620 nm to 750 nm
About this question
Subject: Physics · Chapter: Electronic Devices · Topic: p-n Junction Diode
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