Abstract
Strontium titanate (SrTiO3, STO) is a critically important material for the study of emergent
electronic phases in complex oxides, as well as for the development of applications based on
their heterostructures. Despite the large body of knowledge on STO, there are still many
uncertainties regarding the role of defects in the properties of STO, including their influence
on ferroelectricity in bulk STO and ferromagnetism in STO-based heterostructures. We
present a detailed analysis of the decay of persistent photoconductivity in STO single crystals
with defect concentrations that are relatively low but significantly affect their electronic
properties. The results show that photo-activated electron transport cannot be described by a
superposition of the properties due to independent point defects as current models suggest but
is, instead, governed by defect complexes that interact through dynamic correlations. These
results emphasize the importance of defect correlations for activated electronic transport
properties of semiconducting and insulating perovskite oxides.
