Question

calculate the wavelength of radiation emitted by an led made up of a semiconducting material with band gap energy 1.43eV​

Answer 1

GiveN :

• Energy = 1.43 eV

To FinD :

• Wavelength of radiation emitted

SolutioN :

We know that energy is :

$\underline{\boxed{\sf{E\ =\ h \nu}}}$

$\implies {\sf{E\ =\ \dfrac{hc}{\lambda}}}$

$\implies \sf{1.43\ \times\ 1.6\ \times\ 10^{-19}\ =\ \dfrac{3\ \times\ 10^8\ \times\ 6.62\ \times\ 10^{-34}}{\lambda}}$

$\implies \sf{ 2.28\ \times\ 10^{-19}\ =\ \dfrac{19.86\ \times\ 10^{-26}}{\lambda}}$

$\implies \sf{\lambda\ =\ \dfrac{19.86\ \times\ 10^{-26}}{2.28\ \times\ 10^{-19}}}$

$\implies \sf{\lambda\ =\ 8.7\ \times\ 10^{-7}\ m}$