A solar cell (or panel) is something you'll need to buy. While crude cells can be made at home they have a very limited life span and output. The cell you purchase will indicate the proper wiring.
solar panels are easily available in India (I assume you live there). I am not sure of the quality as I don't use them. I know they are available in Delhi. You can check the local stores in your area, maybe someone can get them for you.
Also I believe an entire solar battery charger system with panel, a sealed lead acid battery, a set of LED lights are available from Government PDS outlets at subsidised prices (you have to check this out).