Is there a cheaper, simpler way to do this?

In terms of cost per watt, the cheapest known way is to buy a ready made solar cell. The one shown here is interesting, but due to the fact that conductive glass is NOT a cheap product - and it produces (according to the photo), a shade under 120 microamps, output is tiny. I do not know the voltage produced - though I would guess between 0.6v and around 1.2v - so the total generated power would be in the order of 72 microwatts and 144 microwatts. To put that into perspective, if we allow the more generous of the two figures above and then round the power up to 150 microwatts, we would still need 20,000 panels to produce enough power to drive a 3w LED lamp.