Two winning entries from the HZB in the Helmholtz Imaging Contest
Keyhole Encounter Insights: This image shows a laser welding process taking place inside metal. A red-hot vapour capillary, also known as a ‘keyhole’, penetrates a cavity filled with pressurised gas and produces blue bubbles in the grey, molten weld. Time-resolved X-ray tomography shows how pores form and trapped gas escapes. This is useful for improving welding strategies. © Paul H. Kamm, HZB, Fraunhofer-Institut IWS, Swiss Light Source.
The colour-coded image shows light emitted by a solar cell. Individual crystals and the boundaries between them are visible, including an almost heart-shaped grain. By measuring this luminescence, it is possible to identify where the material quality is high and where crystal boundaries may impair the solar cell’s performance. © Yannic Kerkhoff, Daniel Abou-Ras, HZB
A time resolved X-ray tomography by Paul H. Kamm, HZB, has won the second prize in this year’s competition. It shows a 3D snapshot of a laser welding process. Among the 20 most beautiful images is also a microscopy image of a solar cell by Yannic Kerkhoff and Daniel Abou Ras, HZB.
From microscopic cellular structures to landscapes viewed from space, images reveal the diversity and beauty of our world – and also help researchers to investigate complex processes and uncover new connections. In the Helmholtz Imaging Best Scientific Image Contest 2026, an independent international jury has once again selected three winning images this year.
First place went to Alena Boos and Nadine Spielmann, Helmholtz Munich, for the image of an embryonic mouse heart. Third place went to Saeid Asadzadeh, GFZ, for a colour-coded satellite image of the Anti-Atlas Mountains in North Africa.
Second place was awarded to the time resolved X-ray tomography image taken by Paul H. Kamm, HZB, at the Swiss Light Source. At first glance, it appears to be a spaceship made of liquid metal floating through space. But what we are actually seeing is a tiny moment during laser welding: This has created what is known as a ‘keyhole’ – a narrow, vapour-filled channel that glows red as it penetrates a cavity densely filled with gas. Blue bubbles form in the grey weld seam. This image is the first three-dimensional observation of such a ‘keyhole’ in action. It shows how molten metal, gas, pressure and surface tension interact within milliseconds. Understanding these processes helps to optimise laser movement, reduce defects and produce stronger, safer welds in die-cast aluminium. The results of this work have been published in the journal Advanced Science (2025): https://doi.org/10.1002/advs.202413108
20 images from a total of 125 entries were selected by the international jury for a travelling exhibition. The exhibition opens at the Helmholtz Imaging Conference 2026 (10–12 November in Leipzig). It will subsequently be on display at Helmholtz Centres and other venues.
Among those selected top 20 images is a colour coded microscopy image from HZB by Yannic Kerkhoff and Daniel Abou-Ras. It shows the light emitted by a polycrystalline CuInSe₂ absorber inside a finished solar cell. Individual crystals and the boundaries between them are clearly visible, including an almost heart-shaped grain. By measuring the luminescence, it is possible to assess the local material quality and determine how grain boundaries influence the efficiency of the solar cell. These findings help to establish a link between the microscopic structure and the performance of the component and contribute to the further optimisation of photovoltaic materials. The image was captured using cathodoluminescence in a scanning electron microscope equipped with a mirror, a spectrometer and a photon detector.
- Israel Ibukun Olaniyan receives the Helmholtz Doctoral Prize 2026At Helmholtz, more than 8,000 doctoral candidates conduct research. Eleven of them have now been honored for their original and outstanding work, among them Dr Israel Ibukun Olaniyan from the HZB. His doctoral thesis "Ferroelectricity at the nanoscale in epitaxial BaTiO3 on silicon" in the group of Professor Catherine Dubourdieu represents a step towards a new nanoelectronics based on topological defects, that can potentially help to create an energy efficient information technology.
- Only at BESSY II worldwide: IR nanoscopy at very long THz wavelengthsThe team at the IRIS beamline at BESSY II has created a new experimental option: They achieved infrared nanoscopy with a spatial resolution of around 50 nm at very long THz wavelengths. This was possible thanks to a temporal pattern of light pulses known as the low-alpha operating mode at BESSY II. Worldwide, BESSY II is the only synchrotron light source at which users could perform nanoscopy in a single setup from 25 to 4000 cm-1, a unique opportunity for ultra-broadband characterisation of complex materials at the nanoscale in both the life sciences and materials sciences.
- Blind spot for the arrangement of atomsArtificial intelligence is increasingly being used to predict the properties of new materials. A research team from Jena and the United States now shows in a study published in the journal Nature Computational Science that when language models are used for this purpose, they reliably identify which types of atoms a material contains. However, they make insufficient use of information about how those atoms are arranged in space. Neither larger models nor additional training data resolve this weakness. For material properties that depend strongly on structure, AI models specifically designed to process spatial relationships are therefore the more reliable choice. (DOI: 10.1038/s43588-026-01045-2)