A facile method of combining the defect engineering with the dielectric-screening effect is proposed to improve the electrical performance of MoS_(2) transistors. It is found that the carrier mobility of the transisto...A facile method of combining the defect engineering with the dielectric-screening effect is proposed to improve the electrical performance of MoS_(2) transistors. It is found that the carrier mobility of the transistor after the sulfur treatment on the MoS_(2) channel is greatly enhanced due to the reduction of the sulfur vacancies during vulcanization of MoS_(2).Furthermore, as compared to those transistors with HfO2 and SiO2 as the gate dielectric, the Al2O3-gate dielectric MoS_(2) FET shows a better electrical performance after the sulfur treatment, with a lowered subthreshold swing of 179.4 m V/dec,an increased on/off ratio of 2.11 × 10^(6), and an enhanced carrier mobility of 64.74 cm^(2)/V·s(about twice increase relative to the non-treated MoS_(2) transistor with SiO2 as the gate dielectric). These are mainly attributed to the fact that a suitable k-value gate dielectric can produce a dominant dielectric-screening effect overwhelming the phonon scattering, increasing the carrier mobility, while a larger k-value gate dielectric will enhance the phonon scattering to counteract the dielectricscreening effect, reducing the carrier mobility.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61774064,61974048,and 61851406)。
文摘A facile method of combining the defect engineering with the dielectric-screening effect is proposed to improve the electrical performance of MoS_(2) transistors. It is found that the carrier mobility of the transistor after the sulfur treatment on the MoS_(2) channel is greatly enhanced due to the reduction of the sulfur vacancies during vulcanization of MoS_(2).Furthermore, as compared to those transistors with HfO2 and SiO2 as the gate dielectric, the Al2O3-gate dielectric MoS_(2) FET shows a better electrical performance after the sulfur treatment, with a lowered subthreshold swing of 179.4 m V/dec,an increased on/off ratio of 2.11 × 10^(6), and an enhanced carrier mobility of 64.74 cm^(2)/V·s(about twice increase relative to the non-treated MoS_(2) transistor with SiO2 as the gate dielectric). These are mainly attributed to the fact that a suitable k-value gate dielectric can produce a dominant dielectric-screening effect overwhelming the phonon scattering, increasing the carrier mobility, while a larger k-value gate dielectric will enhance the phonon scattering to counteract the dielectricscreening effect, reducing the carrier mobility.
