# Photoinduced Domain Pattern Transformation in Ferroelectric/Dielectric Superlattices

## TL;DR

This study demonstrates that above-bandgap optical excitation can induce reversible transformations in ferroelectric/dielectric superlattice domain patterns, driven by charge carrier trapping and screening effects, with observable lattice changes.

## Contribution

It introduces a new understanding of photoinduced domain pattern transformation in ferroelectric superlattices, combining experimental X-ray scattering and theoretical modeling.

## Key findings

- Domain pattern transforms to uniform polarization under optical excitation
- Transformation involves charge carrier trapping and screening
- Lattice expansion correlates with domain disappearance

## Abstract

The nanodomain pattern in ferroelectric/dielectric superlattices transforms to a uniform polarization state under above-bandgap optical excitation. X-ray scattering reveals a disappearance of domain diffuse scattering and an expansion of the lattice. The reappearance of the domain pattern occurs over a period of seconds at room temperature, suggesting a transformation mechanism in which charge carriers in long-lived trap states screen the depolarization field. A Landau-Ginzburg-Devonshire model predicts changes in lattice parameter and a critical carrier concentration for the transformation.

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Source: https://tomesphere.com/paper/1705.01846