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MM: Fachverband Metall- und Materialphysik

MM 4: Materials for the Storage and Conversion of Energy I

MM 4.1: Topical Talk

Montag, 9. März 2026, 10:15–10:45, SCH/A216

Photoelectric properties of dislocations in SrTiO3 single crystals — •Marin Alexe — University of Warwick

Dislocations are one-dimensional crystallographic line defects traditionally regarded as detrimental to the functional properties of conventional semiconductors. However, it has been recently shown on Fe-doped SrTiO3 single crystals containing well-ordered, high-density dislocation structures that dislocations can significantly enhance photoconductivity. Local photoconductivity measurements using atomic force microscopy (AFM) revealed that regions surrounding dislocation cores exhibit up to a fourfold increase in photoconductivity compared with dislocation-free areas of the crystal. Furthermore, macroscopic in-plane surface measurements using microcontacts aligned along dislocation slip bands showed orders-of-magnitude enhancement in photoconductivity. This might be due a significant increase of the carrier density at the core of dislocation due to a to a non-chemical local doping induced by the strain or strain gradient.

These results provide unambiguous evidence that dislocations in oxide semiconductors can be beneficial for specific functional properties. The anisotropic enhancement of photoconductivity along dislocation cores highlights their potential as active elements in future one-dimensional oxide electronic and optoelectronic devices.

Keywords: Photoconductivity; SrTiO3; Dislocation; strain