A typical solar cell consists of a glass or plastic cover or other encapsulant, an antireflective layer, a front contact to allow electrons to enter a circuit, a back contact to allow them to complete the circuit, and the semiconductor layers where the electrons begin and complete their journey.

There are are also many good web resources which explain the science and technology behind solar electric (PV) and thermal systems.  Here are some links that may be useful:


Solar PV Physics

Solar PV Systems

Solar Thermal (hot water) systems