Photodiode

State the reason, why the photodiode is always operated under reverse bias. Write the working principle of operation of a photodiode. The semiconducting material used to fabricate a photodiode, has an energy gap of 1.2 eV. Using calculations, show whether it can detect light of wavelength of 400nm incident on it

Assertion: A P-N photodiode is made from a semiconductor for which E_(g)=2.8 eV . This photo diode will not detect the wavelength of 6000 nm . Reason: A PN photodiode detect wavelength lambda if (hc)/(lambda)gtE_(g) .

Statement-I : A p-n junction with reverse bias can be used as a photodiode to measure light intensity. Statement-II : In a reverse bias condition the current in small but it is more sensitive to changes in incident light intensity.

(i) three photodiodes D_(1),D_(2) and D_(3) are made of semiconductors ahving band gaps of 2.5 eV 2eV and 3eV respecitvely which of them will not be able to detect light of wavelenghth 600nm (ii) why phtoodiodes are required to operate in revese bias explain

Why is a photodide operated in reverse bias mode? Fig. shown reverse bias current, under different illuminating intensities I_(1)I_(2),I_(3) and I_(4) for a given photodiode. Average the intensities I_(1), I_(2),I_(3) and I_(4) in decreasing order of wavelength.