Enhanced vertical piezoelectricity in nano-switch diamane structures by super-dipole-moment effect

The lack of the vertical piezoelectricity and the corresponding internal physical mechanism of diamanes limit their applications in the piezoelectric field. The vertical piezoelectricity of the diamane doped with Si/Ge atoms is studied systematically by the first principles calculation. These monolayer diamanes can be regarded as the vertical piezoelectric nano-switches with a moderate barrier. Based on the 25 kinds of monolayers' data, the super-dipole-moment effect is found as the internal mechanism of larger vertical piezoelectricity based on the ordered phase of Born effective charges. It may deepen the understanding of the internal physical mechanism about the piezoelectricity.