Question

Calculate the wavelength of radiation emitted by an LED made up of a semiconducting

material with band gap energy 2.8eV.

a) 2.8 Å

b) 4.3308 Å

c) 5548.4 Å

d) 4430.8 Å​

Answer 1

Answer:

λ

1

​  

=109678(  

n  

1

2

​  

 

1

​  

−  

n  

2

2

​  

 

1

​  

)

λ

1

​  

=109678(  

2  

2

 

1

​  

−  

3  

2

 

1

​  

)

λ

1

​  

=109678(0.139)=15233cm  

−1

λ=6.56×10  

−5

cm=656nm

Explanation:

Hence, the wavelength of the emitted radiation is 656nm.