Electronic synapses based on ultrathin quasi-two-dimensional gallium oxide memristor
Wang Shuopei1, 2, He Congli1, 3, †, Tang Jian1, 2, Yang Rong1, 4, Shi Dongxia1, 2, 4, Zhang Guangyu1, 2, 4, 5, ‡

(a) Schematic illustration of formation of a thin gallium oxide layer on liquid gallium surface under atmospheric condition. (b) The structure of gallium oxide. (c) Optical microscope image of gallium oxide on a SiO2/Si wafer. Inset: AFM image of gallium oxide on SiO2. (d)–(f) TEM characterization, with HRTEM images and SAED. (g), (h) XPS spectra of the gallium oxide and gallium/gallium oxide mix. (i) XPS spectra of SiO2 substrate with and without GaOx.