Amorphous Silicon Solar Cell

Amorphous silicon, abbreviated a-Si, is the non-crystalline form of silicon used to create solar cells in solar panels and thin-film transistors in liquid-crystal displays. As a semiconductor material for thin-film silicon solar cells, it is deposited in thin films onto flexible substrates such as glass, metal and plastic, though amorphous silicon cells generally feature low efficiency compared with crystalline alternatives. It is considered a second-generation thin-film solar cell technology, and while its share of the worldwide photovoltaic market has declined relative to crystalline silicon and alternative cells such as cadmium telluride and copper indium gallium selenide, it remains in use for the thin-film transistor elements of liquid-crystal displays and for x-ray imagers. Amorphous silicon differs from other allotropic forms of silicon, such as monocrystalline silicon, a single continuous crystal, and polycrystalline silicon, which consists of small grains known as crystallites.