Scientists use piezoelectric electret materials to realize p-MoS2 field effect transistor
Since Geim and others first obtained single-layer graphene in the laboratory in 2004, the emergence of two-dimensional materials has provided the possibility for the further development of the field of sensors. Compared with traditional three-dimensional materials, the layered structure of two-dimensional materials determines The thickness of the device can reach a single atomic layer, which provides the possibility of achieving lighter, thinner and smaller electronic devices. Compared with other two-dimensional materials, the two-dimensional semiconductor TMDs represented by a single layer of molybdenum disulfide (MoS2) due to its excellent semiconductor performance (high switching ratio, mobility), suitable band gap width, high stability, etc. Features make it show advantages in electronic device applications. In addition, the good electrical, optical, mechanical properties and unusual specific surface area of ​​molybdenum disulfide paved the way for sensor applications. Single-layer molybdenum disulfide has a band gap of 1.8 eV. Theoretical calculations show that the mobility and current switching ratio can reach about 410 cm2 / Vs and 109, respectively, at room temperature, which provides its field-effect transistor devices for multifunctional integrated circuit systems. may. Although molybdenum disulfide itself has many excellent properties to meet the needs of future sensor devices in terms of miniaturization, easy integration, thinness, etc., it is not subject to its own piezoresistive and piezoelectric effects. The low sensitivity of the device as a stress sensor is a fact that cannot be ignored. Therefore, it is very important to choose a material that can match the performance of the molybdenum disulfide field effect transistor to achieve its sensing function. As a material that can directly convert external mechanical signals into electrical signals, piezoelectric materials can be combined with field-effect transistors to control external stress on the transport characteristics of the device. Recently, the research team of Sun Qijun, a researcher at the Beijing Institute of Nano-Energy and Systems, Chinese Academy of Sciences, Wang Zhonglin, a foreign academician of the Chinese Academy of Sciences, and Zhang Guangyu, a researcher at the Chinese Academy of Sciences, used the combination of electret materials and molybdenum disulfide field-effect transistors to achieve static / dynamic device Double regulation. Researchers such as Zhao Jing used the piezoelectric-electret characteristics of electret materials (polyvinylidene fluoride-trifluoroethylene, PVDF-TrFE) as gates to realize single-phase alignment under different polarization voltages and strains. The static and dynamic control of the layered molybdenum disulfide field effect transistor results in a stress sensor with high sensitivity, fast response time and long life. Compared with other sensor devices based on field effect transistors, this kind of piezoelectric material itself can directly provide the gate voltage under the effect of stress, and no external gate power supply is needed during the operation of the device, thereby realizing the direct stress to the device The drive effectively reduces energy consumption, and also provides new ideas for the development of passive devices in the future. At the same time, it provides the possibility of subsequent applications in touch screens, artificial electronic skins, and other fields. The related research results were published on ACS nano with the title of Static and Dynamic Piezo-potential Modulation in Piezo-electret Gated MoS2Field Effect Transistor (DOI: 10.1021 / acsnano.8b07477). This work was supported by the National Natural Science Foundation of China and the Beijing Natural Science Foundation. Casting Polyurethane Prepolymer Good Wheel Polyurethane Prepolymer,Casting Polyurethane Prepolymer,Casting Pu For Elastomers,Custom Polyether Polyurethane Prepolymer XUCHUAN CHEMICAL(SUZHOU) CO., LTD , https://www.xuchuanchem.com
Figure: (a) Schematic diagram of the structure of molybdenum disulfide field effect transistor controlled by piezoelectric electret materials; (b) Fluorescence characteristics of molybdenum disulfide under different bending conditions.