Intrinsically asymmetric atomic character regulates piezoelectricity in two-dimensional materials  

作　　者：Yun-Qin Li Qi-Wen He Dai-Song Tang Xiao Shang Xiao-Chun Wang 

机构地区：[1]School of Physics Science and Information Technology,Liaocheng University,Liaocheng 252000,China [2]Key Laboratory of Polar Materials and Devices,Ministry of Education,Department of Electronics,East China Normal University,Shanghai 200241,China [3]Institute of Atomic and Molecular Physics,Jilin University,Changchun 130012,China

出　　处：《Frontiers of physics》2024年第3期153-162,共10页物理学前沿（英文版）

基　　金：the National Natural Science Foundation of China(Grant No.11474123).

摘　　要：Decreasing of layer thickness causes the decrease of polarization until it disappears due to the existence of depolarization field.Therefore,the search for strong piezoelectric materials is highly desirable for multifunctional ultra-thin piezoelectric devices.Herein,we propose a common strategy for achieving strong piezoelectric materials through the electronic asymmetry induced by the intrinsically asymmetric atomic character of different chalcogen atoms.Accordingly,in the tetrahedral lattice structures,for example,M4X3Y3(M=Pd/Ni,X/Y=S,Se or Te,X≠Y)monolayers are proved to display excellent out-of-plane piezoelectricity.Ni4Se3Te3 possesses the largest piezoelectric coefficient d33 of 61.57 pm/V,which is much larger than that of most 2D materials.Enhancing the electronic asymmetry further increases the out-of-plane piezoelectricity of Janus M4X3Y3 materials.Correspondingly,the out-of-plane piezoelectricity is positively correlated with the ratio of electronegativity difference(Red)and the electric dipole moment(P).This work provides alternative materials for energy harvesting nano-devices or self-energized wearable devices,and supplies a valuable guideline for predicting 2D materials with strong out-of-plane piezoelectricity.

关 键 词：PIEZOELECTRICITY intrinsically asymmetric atomic character ratio of electronegativity difference electric dipole moment first-principles calculations 

分 类 号：O17[理学—数学]