Home
Class 12
PHYSICS
An LED is constructed from a p-n junctio...

An LED is constructed from a p-n junction based on a certain semi-conducting material whose energy gap is 1.9 eV. Then, the wavelength of the emitted light is

A

`1.6xx10^(-8)m`

B

`9.1xx10^(-5)m`

C

`2.9xx10^(-9)m`

D

`6.5xx10^(-7)m`

Text Solution

Verified by Experts

The correct Answer is:
D
`E_(g)=1.9eV`
since, `E(eV)=(12400)/(lambda(Å))`
`implieslambda(Å)=(12400)/(1.9)=6526.32Å=6.5xx10^(-7)m`(approx).
Promotional Banner

Similar Questions

Explore conceptually related problems

A p-n junction is fabricated from a semiconductor with band gap of 2.8eV . Can it detect a wavelength of 6000nm ?

A p-n photodiode is fabricated from a semiconductor with band gap of 2.8 eV can it detect a wavelength of 6000 nm

In a gas LED separation between valance band and conduction band is 1.9 eV . Then the light emitted is:

The ground state energy of an atom is -13.6eV . The photon emitted during the transition of electron from n=3 to n=1 state, is incidenet on a photosensitive material of unknown work function. The photoelectrons are emitted from the materials with a maximum kinetic energy of 9 eV. the threshold wavelength of the material used is

A p - n photodiode is fabricated from a semiconductor with band gap of 2.8 eV. Which of the following wavelengths it can detect?