We wish to use a photodiode as a detector for a signal of 9000 A wavelength. ˚ Which would be the best choice of material for the photodiode, a semiconductor of bandgap = 0.5 eV, bandgap = 2 eV, or...

We wish to use a photodiode as a detector for a signal of 9000 A wavelength. ˚

Which would be the best choice of material for the photodiode, a semiconductor of bandgap = 0.5 eV, bandgap = 2 eV, or bandgap = 1 eV? Why? (Assume

all three are direct gap and are equivalent in impurity content, etc.)