Here is a good site to highlight the pitfalls of making your own photovoltaic panels: http://www.diysolar.com/
As I said before, if you want to make your own solar energy from scratch, do it for the fun of it - because its a challenge. The price of ready made solar panels, built in a clean production environment and with a life expectancy of 25 years plus, is falling all the time - its now got to the point where the difference in cost between building your own and buying ready made is just a few dollars for a 60-100 watt panel - so long as you are prepared to spend time to shop around and hunt out the bargains (eBay is a good start, but also check the Amazon marketplace and all the backwater web sites).
Incidentally, I made my own solar hot water system from stuff I had lying around - just for the fun of it, in order to provide hot water for my ancient caravan. It cost me less than $10 and generated about 20 litres of piping hot water on sunny days, but zilch when it was overcast. But hey - for $10, I'm not complaining!