Role of temperature-dependent electron trapping dynamics in the optically driven nanodomain transformation in a PbTiO3/SrTiO3 superlattice

Abstract

The spontaneously formed striped polarization nanodomain configuration of a PbTiO3/SrTiO3 superlattice transforms to a uniform polarization state under the above-bandgap illumination with a time dependence varying with the intensity of optical illumination and a well-defined threshold intensity. The recovery after the end of illumination occurs over a temperature-dependent period of tens of seconds at room temperature and shorter times at elevated temperatures. A model in which the screening of the depolarization field depends on the population of trapped electrons correctly predicts the observed temperature and optical intensity dependence.