Record resolution in X-ray microscopy

December 11, 2020

Researchers at Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), the Paul Scherrer Institute in Switzerland and other institutions in Paris, Hamburg and Basel, have succeeded in setting a new record in X-ray microscopy. With improved diffractive lenses and more precise sample positioning, they were able to achieve spatial resolution in the single-digit nanometre scale. This new dimension in direct imaging could provide significant impulses for research into nanostructures and further advance the development of solar cells and new types of magnetic data storage. The findings have now been published in the renowned journal Optica with the title 'Soft X-ray microscopy with 7 nm resolution'.

Soft X-ray microscopy, which uses low-energy X-rays is used to investigate the properties of materials in the nanoscale. This technology can be used to determine the structure of organic films that play an important role in the development of solar cells and batteries. It also enables chemical processes or catalytic reactions of particles to be observed. The method allows the investigation of so-called spin dynamics. Electrons can not only transport electric charge, but also have an internal direction of rotation, which could be used for new types of magnetic data storage.

To improve research into these processes in the future, researchers need to be able to 'zoom' in to the single-digit nanometre scale. This is theoretically possible with soft X-rays, but up to now it has only been possible to achieve spatial resolution of below 10 nanometres using indirect imaging methods that require subsequent reconstruction. 'For dynamic processes such as chemical reactions or magnetic particle interaction, we need to be able to view the structures directly,' explains Prof. Dr. Rainer Fink from the Chair of Physical Chemistry II at FAU. 'X-ray microscopy is especially suitable for this as it can be used more flexibly in magnetic environments than electron microscopy, for example.'

Improved focusing and calibration

Working with the Paul Scherrer Institute and other institutions in Paris, Hamburg, and Basel, the researchers have now broken a new record in X-ray microscopy as they have succeeded in achieving a record resolution of 7 nanometres in several different experiments. This success is not based primarily on more powerful sources of X-rays, but on improving the focus of the rays using diffractive lenses and more precise calibration of the test samples. 'We optimised the structure size of the Fresnel zone plates which are used to focus X-rays,' explains Rainer Fink. 'In addition, we were able to position the samples in the device at a much higher accuracy and reproduce this accuracy.' It is precisely this limited positioning and the stability of the system as a whole that have prevented improvements in resolution in direct imaging up to now.

Remarkably, this record resolution was not only achieved with specially-designed test structures, but also in practical applications. For example, the researchers studied the magnetic field orientation of iron particles measuring 5 to 20 nanometres with their new optics. Prof. Fink explains: 'We assume that our results will push forward research into energy materials and nanomagnetism in particular. The relevant structure sizes in this fields are often below current resolution limits.'
-end-
The project has received funding from the Federal Ministry of Education and Research (BMBF), the German Research Foundation (DFG) and the EU H 2020 Research and Innovation Programme.

University of Erlangen-Nuremberg

Related Solar Cells Articles from Brightsurf:

Solar cells of the future
Organic solar cells are cheaper to produce and more flexible than their counterparts made of crystalline silicon, but do not offer the same level of efficiency or stability.

A blast of gas for better solar cells
Treating silicon with carbon dioxide gas in plasma processing brings simplicity and control to a key step for making solar cells.

Record efficiency for printed solar cells
A new study reports the highest efficiency ever recorded for full roll-to-roll printed perovskite solar cells.

Next gen solar cells perform better when there's a camera around
A literal ''trick of the light'' can detect imperfections in next-gen solar cells, boosting their efficiency to match that of existing silicon-based versions, researchers have found.

On the trail of organic solar cells' efficiency
Scientists at TU Dresden and Hasselt University in Belgium investigated the physical causes that limit the efficiency of novel solar cells based on organic molecular materials.

Exciting tweaks for organic solar cells
A molecular tweak has improved organic solar cell performance, bringing us closer to cheaper, efficient, and more easily manufactured photovoltaics.

For cheaper solar cells, thinner really is better
Researchers at MIT and at the National Renewable Energy Laboratory (NREL) have outlined a pathway to slashing costs further, this time by slimming down the silicon cells themselves.

Flexible thinking on silicon solar cells
Combining silicon with a highly elastic polymer backing produces solar cells that have record-breaking stretchability and high efficiency.

Perovskite solar cells get an upgrade
Rice University materials scientists find inorganic compounds quench defects in perovskite-based solar cells and expand their tolerance of light, humidity and heat.

Can solar technology kill cancer cells?
Michigan State University scientists have revealed a new way to detect and attack cancer cells using technology traditionally reserved for solar power.

Read More: Solar Cells News and Solar Cells Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.