碲化锗场效应晶体管的制备及电学性能

采用微机械剥离法得到横向尺寸为10μm的碲化锗(GeTe)纳米片.通过电子束曝光和真空溅射镀膜的方法,以钛金合金为接触电极,制备基于二维碲化锗(2D-GeTe)纳米材料的场效应晶体管(FET),并测定了其电学性能.结果表明,剥离所得GeTe纳米材料具有良好的结晶性,光学带隙为1.98 eV,属于p型半导体;该场效应晶体管展现出了6.4 cm2·V-1·s-1的载流子迁移率和670的开关电流比的良好电学性能.

Preparation and Electrical Properties of Germanium Telluride Field Effect Transistor

Compared with three-dimensional(3D) materials, two-dimensional(2D) materials have excellent photoelectric properties, and can be used in many fields such as electronics and photocatalysis, etc. Two-dimensional germanium telluride(2D-GeTe) belongs to a narrow-band gap semiconductor, and its carrier mobility has a theoretical value of up to 1066.33 cm²·V^-1·s^-1, but its crystal structure limits its application in the field of optoelectronics. In this work, a GeTe alloy was synthesized by a high-temperature sintering method in a tube furnace, and then a GeTe nanosheet with a lateral dimension about 10 μm successfully was prepared by micromechanical exfoliation. After heat-treating the material, through the method of electron beam exposure and vacuum sputtering coating, using titanium(10 nm)/gold(60 nm) alloy as the contact electrode, the 2D-GeTe based field effect transistor(FET) was prepared, and the electrical properties were measured at room temperature. The results show that the GeTe nanomaterials obtained by exfoliating have good crystallinity, a wide optical absorption range, and an optical band gap of 1.98 eV, which belongs to p-type semiconductors. At the same time, the FET devices prepared based on 2D-GeTe exhibits favorable electrical properties, with a channel length of 7 μm, a channel width of 3 μm, and a carrier mobility of 6.4 cm²·V^-1·s^-1, the switching current ratio is 670. And the output curve is non-linear, which indicates that due to the preparation process and the environment, there is a clear Schottky barrier between the material and the contact electrode. In short, the study of 2D-GeTe electrical properties and the successful preparation of FET devices have enriched the types of two-dimensional materials in the field of semiconductor optoelectronic devices, and provide some reference and guidance for the research of high optoelectronic devices.