Monocrystalline silicon is one of the most widely used conductor materials for photovoltaic solar panels. A monocrystalline panel is made by using single crystal wafers of silicon and connecting them by wires. [verification needed]
Monocrystalline silicon can be used to generate electricity within solar panels because of the observation of the photovoltaic effect. The photovoltaic effect is caused by the fact that silicon atoms generally don't have full sets of valence electrons in their outer layers, so that electrons coming from the sun's radiant energy can easily move around electrons within a solar cell. This is highly useful because silicon is a relatively common and cheap material that can be used widely in photovoltaic panels, and therefore is one of the primary materials used in photovoltaics.[verification needed]
Monocrystalline silicon differs from polycrystalline silicon in that it is made from a single silicon crystal, either found naturally (very rare) or more commonly synthesized in a lab. Monocrystalline silicon tends to have a slightly higher energy efficiency than polycrystalline silicon[1] which is made from a composite of silicon crystals. However, monocrystalline panels tend to be more expensive and can actually lose efficiency as they increase in temperature. They lose efficiency at higher temperatures because the darker appearance of crystals causes them to absorb more heat than polycrystalline panels, which tend to be a lighter blue color. This is only a concern in high temperature environments.[verification needed]
If return on investment is the primary concern, buyers should invest in polycrystalline panels, as their slightly decreased efficiency is outweighed by their cheaper cost. If money is less of a concern and the investor is most interested in maximizing the power output for a given area, they should invest in monocrystalline panels as they will have a marginally higher rate of electricity production.[verification needed]
