Functional electronic inversion layers at ferroelectric domain walls

• Published in: Nature materials Vol. 16; no. 6; pp. 622 - 627
• Main Authors: Mundy, J. A., Schaab, J., Kumagai, Y., Cano, A., Stengel, M., Krug, I. P., Gottlob, D. M., Doğanay, H., Holtz, M. E., Held, R., Yan, Z., Bourret, E., Schneider, C. M., Schlom, D. G., Muller, D. A., Ramesh, R., Spaldin, N. A., Meier, D.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.06.2017; Nature Publishing Group
• Subjects: 140/146; 639/301/119/995; 639/301/119/996; Biomaterials; Charge transport; Chemical Sciences; Circuits; Compensation; Condensed Matter Physics; Diodes; Domain walls; Electric charge; Electrical resistivity; Electron transport; Electronic properties; Electronic structure; Electronics; Ferroelectric materials; Ferroelectrics; Inversion layers; Magnetic fields; Material chemistry; Materials Science; Nanotechnology; Optical and Electronic Materials; Polarity; Semiconductor devices; Stability; Transistors
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat4878

Ferroelectric domain walls hold great promise as functional two-dimensional materials because of their unusual electronic properties. Particularly intriguing are the so-called charged walls where a polarity mismatch causes local, diverging electrostatic potentials requiring charge compensation and hence a change in the electronic structure. These walls can exhibit significantly enhanced conductivity and serve as a circuit path. The development of all-domain-wall devices, however, also requires walls with controllable output to emulate electronic nano-components such as diodes and transistors. Here we demonstrate electric-field control of the electronic transport at ferroelectric domain walls. We reversibly switch from resistive to conductive behaviour at charged walls in semiconducting ErMnO 3 . We relate the transition to the formation—and eventual activation—of an inversion layer that acts as the channel for the charge transport. The findings provide new insight into the domain-wall physics in ferroelectrics and foreshadow the possibility to design elementary digital devices for all-domain-wall circuitry. Electric-field control of the conductivity of domain walls in ferroelectric ErMnO 3 has been demonstrated. Reversible switching between conducting and insulating states is attributed to an inversion layer, which provides a channel for conduction.