Question

If the energy of a photon of sodium light ( `lambda`=589 nm) equals the band gap of semiconductor, the minimum energy required to create hole electron pair
A. 1.1 eV
B. 2.1 eV
C. 3.2 eV
D. 1.5 eV

Answer 1

Correct Answer - B
Using ,`E=E_g=(hc)/lambda`
`=(6.6xx10^(-34)xx3xx10^8)/(589xx10^(-9))J`
`=(6.6xx10^(-34)xx3xx10^8)/(589xx10^(-9)xx1.6xx10^(-19))`eV =2.1 eV