The PIN photodiode is often used in dose or dose rate monitoring of X or y rays. Comparing with ionization chamber

it has the advantages of small volume

high sensitivity

low cost and no need of high voltage. Unlike counter tubes and scintillation detectors

its current output mode makes it have no dead time in the pulse-mode radiation field. However

the radiation damage by high total dose of exposure affects its performance. The characteristics of PIN photodiode including sensitivity

bias voltage

temperature coefficient

radiation damage and annealing are studied by experiments. Also

a method to deal with the output current is introduced.