The temperature dependence of charge transport dramatically affects and even determines the properties and applications of organic semiconductors, but is challenging to effectively modulate. Here, we develop a strategy to circumvent this challenge through precisely tuning the effective height of the potential barrier of the grain boundary (i.e., potential barrier engineering). This strategy shows that the charge transport exhibits strong temperature dependence when effective potential barrier height reaches maximum at a grain size near to twice the Debye length, and that larger or smaller grain sizes both reduce effective potential barrier height, rendering devices relatively thermostable. Significantly, through this strategy a traditional thermo-stable organic semiconductor (dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene, DNTT) achieves a high thermo-sensitivity (relative current change) of 155, which is far larger than what is expected from a standard thermally-activated carrier transport. As demonstrations, we show that thermo-sensitive OFETs perform as highly sensitive temperature sensors.

Inspired by the gas exfoliation of graphite oxide, a novel airflow sensor is demonstrated with an ultrathin (about 2 nm) reduced graphene oxide (RGO) film with tunable interlayer gaps. The airflow on/off reversibly switches the interlayer gaps of the RGO sheets, and thus changes the electrical conductivity of the RGO film. Remarkably, by virtue of the atomic-scale thickness of the sensing component, RGO sensors show high sensitivity, a wide detection range (tens of mm s⁻¹ to several m s⁻¹), and a low detection limit (26 mm s⁻¹). Such performance is better than that of most of the traditional sensors and near to the capacity of some living beings.