The laptop PCs,modern electronic watches,and calculators use the following for display:

$A$ light emitting diode $(LED)$ is fabricated using $GaAs$ semiconducting material whose band gap is $1.42 \,eV$. The wavelength of light emitted from the $LED$ is: (in $\,nm$)

In a $p-n$ junction solar cell,the value of photo-electromotive force produced by monochromatic light is proportional to the

When an $LED$ is manufactured by using aluminium gallium arsenide $(AlGaAs)$,it emits:

Identify the incorrect statement.

The material used in the fabrication of infrared $LED$'s is