Amorphous silicon thin-film transistors on steel foil substrates

Materials for stretchable electronics

“…4,5 Like any other stiff material, circuits become fl exible and rollable when their thickness is reduced to 1/1000 of the desired radius of curvature. [6][7][8][9] Thinfi lm circuits are made on fl at surfaces by standard microfabrication techniques. When made on plastic substrates and with plastically deformable interconnects, they can be shaped to surfaces that need expansion out of the plane, for instance spherical caps.…”

“…20,21 Now we can make electronic skin, 22 conformable sensors and displays (see the Kim et al and Sekitani and Someya articles in this issue), electronic biointerfaces, 12,[23][24][25] electronic muscles, 20,21,26 and energy harvesters (see the article by Kornbluh et al in this issue). Bending, [7][8][9] shaping, 10,27 stretching (see the Suo article), 11 and electroactuation 20,21 or energy harvesting are illustrated in Figure 1 . The latest progression is circuits made on a biodegradable substrate, 28,29-31 which disappears to leave the bare circuit conforming to a living organism; the goal is a circuit that envelopes the heart fully to sense and stimulate it with high spatial resolution while expanding and shrinking with the heartbeat.…”

High-performance hydrogenated amorphous silicon TFT on flexible metal foil with polyimide planarization

“…Therefore, new substrates as replacements have been strongly required to make a flexible, rugged, and lightweight flat panel display [3,4]. As alternate substrates, metal foil, flexible glass, and plastic substrates have been proposed [5][6][7]. To ensure high-performance backplanes to drive OLEDs, the TFT fabrication (whether amorphous Si or poly-Si) must be performed at around 300°C or above.…”

Hydrogenation assisted nickel-induced lateral nano-crystallization of amorphous silicon on flexible plastic substrates at low temperatures

“…Although single crystalline silicon wafers are the most widely used substrates for large-scale integrated electronic applications, amorphous and polycrystalline-silicon films are desirable in applications where flexibility and cost restrictions are important factors, such as solar cells [1] or thin-film transistor (TFT) drivers in liquid-crystal displays [2]. In these applications, often low-cost glass or kapton substrates are coated with an amorphous silicon layer and crystallization of the layer is achieved by subsequent annealing using methods such as solidphase crystallization (SPC) or excimer-laser annealing [3][4].…”