Why does a photodiode function in reverse bias?

Why does a photo-diode function in reverse bias?

Why is photodiode used in reverse bias ?

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.

Why should a photodiode br operated in reverse biased mode?

What is a photodiode why is it kept in reverse bias for operation while the current available in forward bias happens to be more

The current in the forward bias is known to be more (in mA ) than the current in the reverse bias (in mu A ). What is the reason then to operate the photodiodes in reverse bias?

The current in the forward bias is known to be more (in mA ) than the current in the reverse bias (in mu A ). What is the reason then to operate the photodiodes in reverse bias?