Theoretical analysis on the extension of a piezoelectric semi-conductor nanowire: Effects of flexoelectricity and strain gradient

Abstract

One-dimensional piezoelectric semiconductor (PSC) nanowires have been widely used in smart structures and devices; however, few theoretical studies on their nano-size effects have been carried out. In this paper, a theoretical analysis of one-dimensional n-type PSC nanowires under an axial force was carried out, with consideration of the flexoelectric and strain gradient effects. Exact solutions were obtained based on the differential operator theory. The flexoelectric and strain gradient effects on the internal electromechanical field and carrier concentration have been discussed. It can be shown that the flexoelectric effect weakens the piezoelectricity of a PSC nanowire while the strain gradient has the opposite effect, with an amplitude enhancement that is dependent on the flexoelectric and inner scale coefficients.