Stable nanobubble domains confined to the ferroelectric PMN-xPT single crystal’s surface are created by an applied electric field. Under above-bandgap illumination, these features remain unchanged, but upon cessation of illumination, they expand rapidly to switch the entire crystal surface, accompanied by a ≈ −5 V surface potential jump, pointing to a large reservoir of electrons at the crystal surface.
Image Credit: Courtesy of Flinders University / et al.; Advanced Functional Materials 2026
Scientific Frontline: Extended "At a Glance" Summary: Post-Illumination Switching in Ferroelectric Crystals
The Core Concept: Light can control nanoscale "bubble" domains within specific ferroelectric crystals, with the primary electronic structural changes occurring entirely after the light source is removed.
Key Distinction/Mechanism: Unlike conventional materials that undergo changes actively during light exposure, these ferroelectric crystals accumulate a reservoir of electrons near their surface while illuminated. When the light is switched off, the electrons are suddenly released, triggering a rapid expansion of the nanoscale domains and instantly switching the electronic state of the crystal's surface.
Major Frameworks/Components:
- PMN-xPT single crystals: The highly specific ferroelectric material utilized to host and confine the stable nanobubble domains.
- Above-bandgap illumination: The precise optical stimulation method used to mobilize and gather charge carriers without immediately altering the physical nanostructures.
- Surface potential jump: A documented voltage shift of approximately −5 V that occurs the moment illumination ceases, confirming the sudden release of surface electrons.
Branch of Science: Condensed Matter Physics, Materials Science, Nanoscale Science, and Optical Science.
Future Application: The mechanism provides a foundation for faster, highly efficient optoelectronic technologies, including non-volatile memory, next-generation computing, sensors, and artificial intelligence hardware.
Why It Matters: Because the critical switching mechanism occurs after the energy source (light) is removed, this approach has the potential to drastically reduce energy consumption and eliminate the unwanted thermal heating that plagues conventional light-controlled devices.
An applied electric field creates stable nanobubble domains confined to the surface of the ferroelectric PMN-xPT single crystal. Under above-bandgap illumination, these features remain unchanged; however, upon the cessation of illumination, they expand rapidly to switch the entire crystal surface. This expansion is accompanied by a surface potential jump of approximately −5 V, pointing to a large reservoir of electrons at the crystal surface.
Researchers at Flinders University have discovered an unexpected way that light can control tiny electronic structures inside advanced materials, a development that could help pave the way for more energy-efficient memory devices, sensors, and future computing technologies.
The new study, involving experts from around the world, seeks inroads into electronic properties and optical science by exploring new energy and material capabilities.
“We discovered that light can control nanoscale ‘bubble’ domains (about the size of just a few billionths of a meter across) inside a special ferroelectric crystal,” says Dr. Pankaj Sharma, senior lecturer in experimental condensed matter physics at Flinders University. “However, while most materials respond while the light is shining on them, what surprised us was that the biggest change happened after the light was switched off. By engineering these nanoscale structures, we may be able to develop faster and more efficient electronic and optoelectronic technologies.”
The study, published in Advanced Functional Materials, was led by Dr. Haoze Zhang, a postdoctoral fellow in the Sharma research group at Flinders University’s College of Science and Engineering.
While the nanodomains responded only in a minor way when illuminated with near-visible light, they rapidly expanded the moment the light was switched off. This temporarily switched the electronic state of the crystal’s surface before the nanodomains gradually returned to their original configuration.
“This behavior is unlike anything we have seen before,” says Dr. Zhang. “It reveals a completely new way that light and electronic structures interact inside ferroelectric materials.”
Using advanced microscopy and electrical measurements, the Flinders researchers, along with collaborators from UNSW Sydney, India, and the United States, tracked how electrical charges move through the material during and after illumination. They found that electrons accumulate near the surface while the light is on and are suddenly released when the light is removed, triggering the rapid switching process.
Ferroelectric materials are emerging for promising new applications in next-generation computing, nonvolatile memory, artificial intelligence hardware, sensors, and photonic devices.
“Because the switching occurs after the light is removed, the approach could reduce energy consumption and minimize unwanted heating compared with conventional light-controlled devices,” adds Dr. Zhang.
Funding: The research was supported by the Australian Research Council Discovery Projects (DP240102137, DP240100238), the Flinders Microscopy and Microanalysis facility, Microscopy Australia, the Electron Microscope Unit, the Mark Wainwright Analytical Center, UNSW Sydney, and Flinders University.
Published in journal: Advanced Functional Materials
Title: Effect of Optical Illumination on Bubble Nanodomains
Authors: Haoze Zhang, Anju Ahlawat, Richard F. Webster, Yunlong Sun, Dinesh Shukla, Danyang Wang, Jan Seidel, Alexei Gruverman, and Pankaj Sharma
Source/Credit: Flinders University
Edited by: Scientific Frontline
Reference Number: phy080326_01
