Researchers at the Oak Ridge National Laboratory in the US have developed a new technique for high speed voltage measurements at the atomic level using machine learning. The technique has reportedly been used for mapping surface voltage dynamics of a perovskite solar cell for the first time.
Atomic force microscopy can usually investigate slow or static material structures and functions. In AFM, a rastering probe maps a material's surface and captures physical and chemical properties but the probe is slow to respond to what it detects. Instead, the ORNL team created a fast free force recovery technique that uses advanced machine learning algorithms to analyze instantaneous tip motion to produce high-resolution images 3,500 times faster than standard AFM detection methods.
"This new approach can probe fast processes, such as charge screening, ionic transport and electrochemical phenomena, which were previously inaccessible with traditional AFM," said the ORNL team. The technique has been used to map the surface voltage dynamics from ion migration induced by an electric field in a perovskite solar cell.