The receiver sensitivity is not explicitly shown or set within the PIN Photodiode, as it depends on the users definition (which Q factor is chosen as the threshold). However, the noise and bandwidth which can be set within the Photodiode changes the sensitivity of the photodiode and a nice little example of this is found at this link:
http://psut.edu.jo/sites/yazan/classes/Spring2010/MicrowaveLab/FExp4.pdf
Let me know if this helps!