Piezoelectric coupling strength

In this paper, we present the lateral size dependence of Huang-Rhys factors for the QW heterostructures with the localized quasi-2D excitonic states. The Huang-Rhys factor is a quantity representing the coupling strength of a localized particle with phonons [4]. All exciton-phonon interaction mechanisms are analyzed. They are the polar optic (Froehlich) interaction, the optic deformation potential, the acoustic deformation potential, and the acoustic piezoelectric interaction. We would... 

Piezoelectric coupling factors (e.g. and k refer to the overall strength of... 

The fundamental considerations of Chapter 3 are independent of the properties of the materials and therefore are not sufficient to describe the behavior of the mechanical or electrostatic system. The missing links are the constitutive relations between stresses and strains on the mechanical side, between flux density and field strength on the electrostatic side, and the connection between the mechanical and electrostatic side. Effects like piezoelectricity couple the mechanical and electrostatic fields. For the subsequent considerations identical material properties at every location of the continuum can be presumed due to its macroscopic homogeneity. 

The subsequent characterization of electromechanical coupling covers the various classes of piezoelectric materials. Details with respect to definition and determination of the constants describing these materials have been standardized by the Institute of Electrical and Electronics Engineers [f04]. Stresses flux density D and field strength E on the electrostatic side, may be arbitrarily combined into four forms of coupled constitutive equations ... 

In the structure of the constitutive equation for the mechanically and electrostatically orthotropic piezoelectric material of Eq. (4.17), the partial coupling needs to be noted. The normal stresses and strains in all three directions are solely connected to flux density and field strength along the polarization direction ... 

To increase the electromechanical coupling and allow for anisotropic and thus directional actuation and sensing, the concept of interdigitated electrodes has been introduced by Hagood et al. [90] for monolithic piezoelectric laminae, as shown in Figure 5.2(b). Thereby in-plane placement of the parallel directions of polarization and electric field strength is permitted. These directions... 

These assumptions can be applied immediately in the directions ei and 2 of the cross-sectional plane of the fibers. As the constitutive relation of the considered piezoelectric materials exhibits only a partial electromechanical coupling, normal modes and each of the shear modes may be treated independently, as illustrated by Eqs. (4.19) to (4.21). In accordance with the considerations of Section 4.4.4, the notation with negated electric field strength and the associated constitutive submatrices E, Gi, and G2 will be utilized. 

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