Photovoltaic Silicon Wafer

A solar cell is a type of semiconductor that directly converts sunlight into electricity. Almost all semiconductors use single-crystalline silicon as the raw material, and many current solar cells now use crystalline silicon.
SUMCO supplies silicon wafers for solar cells along with silicon wafers for semiconductors all over the world.

The most popular solar cells at present use silicon, which is also used for semiconductors.
Exposure of silicon to light generates holes with an electrically positive property and electrons with a negative property. This is called the photovoltaic effect. However, simply generating electrons and holes does not allow taking out electricity, and they also disappear immediately.

There are two types of silicon: p-type silicon in which holes gather and n-type silicon in which electrons gather. A solar cell consists of piled p- and n-type silicon layers. Therefore the generated holes is attracted by the p-type silicon layer, and the electrons is attracted by the n-type silicon layer. Thus the condition is the same as that of the + and - sides of a battery.

Each surface of the p-type silicon and n-type silicon is provided with an electrode for taking out the electricity generated by the solar cell. The connection of electrical wires to the electrodes enables the use of electric energy. Although it may seem difficult to understand because of the unfamiliar terms, the mechanism is extremely simple where exposure to light generates electricity.