An ideal photodiode is made of a material with a bandgap energy of \(2.35 \mathrm{eV}\). It operates at \(300 \mathrm{~K}\) and is illuminated by monochromatic light with wavelength of \(400 \mathrm{~nm}\). What is its maximum efficiency?

Although each photon has an energy \(h v\) it will produce only \(h v_{g}\) units of electric energy, with \(v_{g}\) being the frequency associated with the bandgap.