Electronic Devices and Circuits - Engineering

Q1:

Given that the band gap of cadmium sulphide is 2.5 eV, the maximum photon wavelength, for e--hole pair generation will be

A 5400 mm

B 540 mm

C 5400 Å

D 540 Å

ANS:C - 5400 Å

E = hf.
f = E/h = 2.5eV (1.6E-19J)/h.
λ = c/f = 5000 angstroms

Correct me if I'm wrong.