These holes are also mobile, and both the electrons and holes carry electrical charge. As they travel, their motion subtly distorts the surrounding atomic lattice. <\/p>\n
However, this deformation, which was once impossible to detect, has now been captured with the help of femtosecond-scale X-ray pulses<\/a>. The images revealed how electron-hole pairs interact with the crystal lattice on ultrafast timescales.<\/p>\n The researchers then studied a quantum dot<\/a> made of cesium, lead, and bromine (CsPbBr3), measuring just millionths of a millimeter across. The quantum dot, essentially a semiconductor particle, is so small that its behavior can only be explained through quantum mechanics.<\/p>\n They discovered that electron-hole pairs are created when light hits the quantum dot. These then tug at the surrounding atoms, creating a \u2018dent\u2019 in the crystal lattice, producing a state known as an exciton-polaron.<\/p>\n New technology on the rise<\/p>\n According to Zhou Shen, PhD, a researcher at the Max Planck Institute for the Structure and Dynamics of Matter and lead author of the study, even though the lattice deformation only affects a few atoms, it is decisive for the optical and electronic properties of the material.<\/p>\n \u201cThe better we understand the deformation, the better we can try to develop improved materials, for example, for more efficient displays or more powerful sensors,\u201d Shen explained.<\/p>\n Bielecki added that detecting the lattice deformation required an exceptionally precise method, which the team achieved using the European XFEL in Schenefeld near Hamburg, Germany.<\/p>\n Reportedly, the world\u2019s\u00a0largest X-ray laser<\/a>\u00a0emits ultra-short, high-intensity flashes that allow images to be captured within femtoseconds (a quadrillionth of a second).<\/p>\n Dubbing the direct observation of this effect a scientific masterpiece, the team emphasized its importance for understanding how light and matter interact at the smallest scale. <\/p>\n They believe the data is crucial for future technologies, including ultra-sensitive light detectors and advanced displays, and components for quantum computers.<\/p>\n \u201cWhat we show here is a first step towards specifically controlling such effects,\u201d Shen concluded in a press release<\/a>. \u201cThis could enable us to develop even more powerful and energy-saving optoelectronic components in the future.\u201d<\/p>\n![\"\"](\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/08\/PulseOnly_1600x900-1.jpg\")
An incoming X-ray light wave (left) made up of a chaotic distribution of very fast spikes interacts with atoms (purple dots) in a gas to amplify specific spikes (right) in the light wave.
Credit: Stacy Huang\/Argonne National Laboratory<\/a><\/p>\n