TFT

Thin-film transistor (TFT) refers to a type of transistor used as the switching element in active-matrix display technologies, most notably TFT LCDs. In an active-matrix display, each pixel is controlled by its own transistor and a storage capacitor, forming a pixel-addressable backplane. This arrangement provides faster addressing, improved charge retention, higher contrast, and better motion response than passive-matrix designs.

TFTs are fabricated on insulating substrates such as glass and use thin films of semiconductor material, commonly amorphous silicon (a-Si) or polycrystalline silicon (poly-Si). The transistor’s source, drain, and gate are patterned to form a dense array beneath the pixel circuitry. The backplane controls the pixel by applying voltages that modulate the alignment of the liquid crystal molecules, producing varying light transmission.

Advances in TFT technology include low-temperature polycrystalline silicon (LTPS) and oxide-semiconductor TFTs (such as IGZO), which offer higher electron mobility and enable higher-resolution, higher-brightness displays with lower power consumption. TFT backplanes are widely used in televisions, computer monitors, smartphones, tablets, and other devices requiring high-quality LCD images. The technology is also used in some OLED displays that employ a thin-film transistor-based backplane for precise pixel control.

Other uses of the acronym TFT exist outside this context, including Teamfight Tactics, an online strategy game by Riot Games. In display technology, however, TFT almost always refers to thin-film transistors used in active-matrix LCD backplanes.