Free-Carrier-Compensated Charged Domain Walls Produced with Super-Bandgap Illumination in Insulating Ferroelectrics

Charged domain walls in ferroelectrics are movable and electronically conducting interfaces inside insulating materials. A simple and reliable method for their artificial production with ultraviolet (UV) light is described. The UV illumination produces free carriers in ferroelectric bulk, which simultaneously promotes the formation of charged domain walls and provides charge for their compensation.