Question
Question: Three photo diodes \(D_{1},\) \(D_{2}\) and \(D_{3}\) are made of semiconductors having bandgap of \...
Three photo diodes D1, D2 and D3 are made of semiconductors having bandgap of 2.5eV, 2 eV and 3 eV, respectively. Which one will be able to detect light of wavelength 6000Ao?
A
D1
B
D2
C
D3
D
D1 and D2 both
Answer
D2
Explanation
Solution
: Energy of incident photon,
E=λhc
=6×10−7×1.6×10−196.6×10−34×3×108=2.06eV
The incident radiation can be detected by a photodiode if energy of incident photon is greater than the band gap.
As , D2=2eV
∴D2will detect these radiations .