The thermoelectric power of a material, typically governed by its band structure and carrier density, can be varied by chemical doping that is often restricted by solubility of the dopant. Materials showing large thermoelectric power are useful for many industrial applications, such as the heat-to-electricity conversion and the thermoelectric cooling device. Here we show a full electric-field tuning of thermoelectric power in a dual-gated bilayer graphene device resulting from the opening of a band gap by applying a perpendicular electric field on bilayer graphene. We uncover a large enhancement in thermoelectric power at a low temperature, which may open up a new possibility in low temperature thermoelectric application using graphene-based device.

Amorphous-silicon (a-Si) thin-film transistors (TFTs) were fabricated on a free-standing new clear plastic substrate with high glass transition temperature (Tg) of >315° C and low coefficient of thermal expansion of <10 ppm/ ° C. Maximum process temperatures on the substrates were 250°C and 280°C, close to the temperatures used in industrial a-Si TFT production on glass substrates. The first TFTs made at 280°C have dc characteristics comparable to TFTs made on glass. The stability of the 250°C TFTs on clear plastic is approaching that of TFTs made on glass at 300°C-350°C. TFT characteristics and stability depend only on process temperature and not on substrate type

Field-effect structures were made from nanocrystalline silicon (nc-Si:H) deposited at a substrate temperature of 150 °C by plasma-enhanced chemical vapor deposition excited at 80 MHz. The nc-Si:H channel layer was grown on top of a separate nc-Si:H buffer and seed layer that serves to develop the crystalline structure. Staggering the contacts and the gate ensures that mobilities are measured precisely in the last-to-grow nc-Si:H layer. The hole mobility in saturation reaches 0.06–0.2 cm² V⁻¹ s⁻¹ and the electron mobility ∼12 cm² V⁻¹ s⁻¹. These results suggest that large-area circuits of complementary p- and n-channel devices can be made from nc-Si:H deposited on low-temperature substrates.