...sorry, you cannot view external links. To see them, please REGISTER or LOGIN
Solar photovoltaic panels
Crystalline silicon and gallium arsenide are typical choices of materials for solar cells. Gallium arsenide crystals are grown especially for photovoltaic use, while silicon crystals are available in less-expensive standard ingots. These ingots are produced mainly for consumption in the microelectronics industry. Polycrystalline silicon has lower conversion efficiency but also lower cost.
Crystalline ingots are sliced into wafer-thin disks, polished to remove slicing damage, dopants are introduced into the wafers, and metallic conductors are deposited onto each surface: a thin grid on the sun-facing side and usually a flat sheet on the other. Solar panels are constructed of these cells cut into appropriate shapes, protected from radiation and handling damage on the front surface by bonding on a cover glass, and cemented onto a substrate (either a rigid panel or a flexible blanket). Electrical connections are made in series or in parallel to determine total output voltage. The cement and the substrate must be thermally conductive, because the cells heat up from absorbing infrared energy that is not converted to electricity. Since cell heating reduces the operating efficiency it is desirable to minimize the heating. The resulting assemblies are called solar panels or solar arrays.n