Solution-processed ambipolar ionic-gated transistors from 1D/2D heterojunctions of WSe2 and self-conversed SnO2/Se enabling high-sensitivity thermal sensing

Ambipolar transistors from low-dimensional semiconductors with high charge-transporting capability and tunable bandgap have developed rapidly in functional applications, such as neuromorphic computing, lighting, storing, and sensing. However, there are still challenges to balance procedure complexity and device performance, such as current on–off ratio, work voltage, and operational reliability. Here, we demonstrated solution-processed ambipolar ionic-gated transistors (amIGTs) from stacked heterojunctions of 1D/2D SnO2/Se composites and 2D WSe2 nanosheets, with high current on–off ratios, low work voltage, and high operational stability. The 1D/2D SnO2/Se composite, involving 1D SeNWs and 2D SnO2 nanosheets, was directly obtained by a one-step self-conversion from 2D SnSe nanosheets. We found that charge transports in SnO2/Se were greatly improved by formed efficient channels of 1D SeNWs, giving the extremely low value of subthreshold swing (SS) of reaches as low as 68 mV/dec, very close to the limitation (60 mV/dec) of “Boltzmann theory.” Using the amIGTs, we achieved highly stable and operation-tunable thermal sensing, with a high sensitivity of 16%/K, high resolution of 0.1 K, and a large linear detection range of 100 K. Our results hold great implications for wide applications of the low-dimensional material-based transistors in the post-Moore era.