Cells Panels Arrays

I need to describe the construction, explain the opperation and give one detailed example of the use of a large area photodiode.

I wrote this report and did it on solar panel cells and have been told that the cells which make up solar panaels are not arrays of large area photodiodes. So im totaly stumped on what these are and what they are used for! Please help if you can.
Hi Frank

I have done and that wiki page is basically wrong from teh seem of it. Its wahts caused all the confusion. Its looking like a LA PD is actually what recieves an IR signal and converts it to electricity. The person who wrote that on wiki was on the right lines, but the answer i got back from an op[tics teacher is thats its a very cruid application of it.