| Affiliation: | 1. School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081 China;2. State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing, 100871 China;3. Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China;4. School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081 China
School of Aerospace Engineering, Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing, 100081 China;5. School of Aerospace Engineering, Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing, 100081 China;6. College of Physics and Optoelectronics, Faculty of Science, Beijing University of Technology, Beijing, 100124 China |
| Abstract: | Most atomically thin piezoelectrics suffer from weak piezoelectric response or current rectification along the thickness direction, which largely hinders their applications in a vertical crossbar architecture. Therefore, exploring new types of ultrathin materials with strong longitudinal piezoelectric coefficient and rectification is highly desired. In this study, the monolayer of van der Waals CuInP2S6 (CIPS) is successfully exfoliated and its strong piezoelectricity in the out-of-plane direction with an effective coefficient d33eff of ≈5.12 pm V?1, which is one or two orders of magnitude higher than that of most existing monolayer materials with intrinsic d33, is confirmed. A prototype vertical device is further constructed and the current rectification is achieved through the flexoelectricity induced by the scanning tip force. The switching between low and high rectification states can be readily controlled by tuning the mechanical loads. These findings manifest that CIPS possesses promising application in vertical nanoscale piezoelectric devices and provides a novel strategy for achieving a good current rectification in ultrathin piezoelectrics. |
