The triboelectric microplasma transistor of monolayer graphene with a reversible oxygen ion floating gate

Using the adsorbates as a floating gate on graphene is an importance strategy for developing novel field effect transistor. However, O2, as the most common and active gas in air, has not been used as floating gate of graphene transistor, since its lowest unoccupied molecular orbital (LUMO) is higher than the Fermi level of graphene, blocking the formation of O2− ions. Here, the graphene transistor using O2− as a reversible floating ion gate has been reported by introducing triboelectric microplasma to activate the adsorption path, where O2 molecule is activated into O2− ion before its adsorption. The adsorbed O2− with a concentration of 3.45 × 1012 cm−2 has been realized in the experiment, acting as a negative floating gate to move down Fermi level and produce p-type doping of graphene. The floating gate of O2− is reversible, which can be erased by heating and the desorption barrier is calculated as 198 meV. The ab initio simulation shows that, the LUMO level of the adsorbed O2− is lowered to 0.85 eV below the Fermi level of graphene, which overcomes the barrier in the adsorption path with microplasma. The experiments results have demostrated that the triboelectric microplasma technology has potential applications in developing novel electronic and optoelectronic devices.