Your question is very open as photodiodes have so many applications.

To answer your question   : 

• the current of a photodiode is fairly proportionnal to the active surface of the device
• the lowest value of the current is when the diode is in the dark, on some components it can be as low as 30pA
• the highest value in full light can be as high as several Amps if the photodiode is used to produce electrical energy.

you migh also want to have a look at :

http://www.thorlabs.de/newgrouppage9.cfm?objectgroup_id=285

http://uk.rs-online.com/web/generalDisplay.html?id=electronics/ssl&file=photodiodes

thanks for details

ya you are true , qstion is open 

i am working on didoe based on oxide and on organic materials. My devices are fabricated by ourself, I ph is around 10µA and Voc is very low