Domain wall scattering determining the transmittance of transparent ferroelectric crystals

Transparent ferroelectric materials have been attracting enormous attention due to their simultaneously ultrahigh transparency and piezoelectricity, which are highly desirable for electro-optical-mechanical devices. However, it is very challenging to achieve excellent optical transparency in ferroelectric materials because of the severe light scattering of the domain wall. Here, a domain wall scattering model is developed to reveal the mechanism of light scattering caused by domain walls and to quantitatively calculate the scattering of light by different domain walls. The reliability of such a model is verified by the good agreement between theoretical predictions and recent experimental measurements. Based on the model, both domain wall type and orientation are found to greatly determine the transmittance of transparent ferroelectric crystals. The influence of domain size is also investigated. This work provides a theoretical basis for regulating the transmittance of transparent ferroelectric crystals through domain wall engineering.