Mixed‐Dimensional van der Waals Engineering for Charge Transfer Enables Wafer‐Level Flexible Electronics

Flexible electronics draw intense interest because of their promising potential for emerging applications, which, however, encounter challenging obstacles of material self‐limiting fabrication, trade‐off mechanical flexibility, and associated moderate electrical performance. Here, wafer‐level flexible fully‐carbon‐integrated transistors via mixed‐dimensional van der Waals (vdW) engineering is realized. Remarkable performance includes subthreshold swing of 51.8 mV dec−1 breaking thermionic limit, outstanding field‐effect mobility as high as 313.8 cm2 V−1 s−1, and sub‐1 V operating voltage. The charge transfer modulation of graphene oxide on carbon nanotube in the vdW‐integrated transistors is designed to enhance channel conductance, which is simultaneously confirmed by theoretical calculations and electrical characterizations. Besides, the transistors maintain stable electrical performance after bending under an ultra‐small radius of 250 µm. Exponential‐sensitivity temperature sensors and binary‐logic inverters are further realized to demonstrate the feasibility of the devices as the building blocks of all‐vdW electronics. These results indicate that either the strategy of all‐vdW transistor realization or the charge transfer provides general approach to improve device performance and further advance flexible electronic technologies. Flexible fully‐carbon‐integrated transistors are realized based on mixed‐dimensional van der Waals (vdW) heterojunctions. This work combines the advantages of vdW engineering and carbon‐based materials, achieves expected electrical and mechanical performance, and studies the charge transfer mechanism involved. Either the strategy for all‐vdW transistor realization or the charge transfer mechanism provides general approach to improve device performance.