Performance Improvement of Multi-layered SnS2 Field Effect Transistors through Synergistic Effect of Vacancy Repairing and Electron Doping Introduced by EDTA

Tin disulfide (SnS2) has a larger band gap (>2.0 eV) than other two-dimensional (2D) materials, which can achieve a higher on/off current ratio, a much lower off-current and standby power dissipation in future electronics. However, the defects in SnS2 such as sulfur vacancies always result in very low carrier mobility and on/off current ratio, which are far behind their theoretical values. Herein, we report a synergistic effect of vacancy repairing and electron doping on SnS2 sheets introduced by ethylenediaminetetraacetic acid (EDTA) molecules decoration, which improves the electrical performance of FETs devices. XPS measurements reveal the EDTA can coordinate with the stannum atom at the sulfur vacancy thereby repairing it, while the Hall effect measurements show 1 order improvement of electron concentration and Hall mobility, up to 4.14×1013/cm2 and 237.1 cm2/V·s after 0.3 mol/L EDTA treatment, respectively. Meanwhile, the top-gate FETs with h-BN dielectric layer demonstrate a promising field effect mo...