Nanoparticle-based flexible inverters with a vertical structure

•A vertical inverter made of HgTe and HgSe nanoparticle-based thin film transistors•The typical inverter characteristics with a gain of 4•The gain maintained even after 1000 bending cycles

We report the construction and characterization of a representative vertical inverter with a nanoparticle (NP)-based p-channel thin-film transistor (TFT) and a NP-based n-channel TFT on a flexible substrate. The vertical inverter consists of a p-type HgTe NP-based TFT on the first-stair layer and an n-type HgSe NP-based TFT on the second-stair layer. In the vertical inverter, an isolation layer made of polyvinyl alcohol prevents the cross talk between these TFTs. The vertical inverter exhibits the typical inverter characteristics with a gain of 4, and the reproducible operation was obtained in the upward and downward bending states, as well as in the flat state. Moreover, the inverter characteristics were maintained even after 1000 bending cycles with 0.7% strain.