Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

High-performance solar cells: physicists from Halle grow stable perovskite layers

06.11.2018

Crystalline perovskite cells are the key to cutting-edge thin-film solar cells. Although they already achieve very high levels of efficiency in the laboratory, commercial applications are hampered by the fact that the material is still too unstable. Furthermore, there is no reliable industrial production process for perovskites. In a new study published in the "Journal of Physical Chemistry Letters", physicists at Martin Luther University Halle-Wittenberg (MLU) present an approach that could solve this problem. They also describe in detail how perovskites form and decay. The results could help produce high-performance solar cells in the future.

Perovskites are currently receiving a great deal of attention in the solar industry. In 2009, researchers were first able to prove that organic-inorganic compounds with a special perovskite crystal structure are good absorbers that can effectively convert sunlight into electricity. Within just a few years, the efficiency of perovskite solar cells was increased to well over 20 percent in the laboratory.


"Although modern, monocrystalline silicon solar cells achieve slightly better values, they are much harder to manufacture and they have been under development for a much longer time," says Dr Paul Pistor, a physicist at MLU and lead author of the study. Currently, however, there are no market-ready perovskite-based solar cells as there is no established process for the large-scale production of perovskites.

In addition, the thin crystal layers are rather unstable and sensitive to environmental influences. "High temperatures or humidity cause the perovskites to decompose and lose their ability to convert sunlight into electricity," says Pistor. Yet, solar cells have to withstand elevated temperatures because they are permanently exposed to the sun.

In their study, the physicists from Halle investigated a special, inorganic perovskite consisting of caesium, lead and bromine or iodine. Instead of using the usual wet-chemical processes to produce the perovskites, they deployed a process that is already widely used in industry to produce thin layers and a range of components.

In a vacuum chamber, precursor materials are heated up until they evaporate. Then, the perovskite condenses on a colder glass substrate and a thin crystalline layer grows. "The advantage of this method is that every part of the process can be very well controlled. This way, the layers grow very homogenous and the thickness and composition of the crystals can be easily adjusted," explains Pistor.

His team was thus able to produce perovskite layers based on caesium that didn’t decompose until they reached temperatures of 360 degrees Celsius. Using cutting-edge X-ray analysis, the researchers also analysed the growth and decay processes of the crystals in real time.

The results provide important insights into the underlying properties of perovskites and point to a process that may be suitable for the industrial realisation of modern perovskite-based solar cell technology.

Originalpublikation:

Burwig T., Fränzel W., Pistor P., Crystal Phases and Thermal Stability of Co-evaporated CsPbX3 (X = I, Br) Thin Films, Journal of Physical Chemistry Letters (2018), doi: 10.1021/acs.jpclett.8b02059

Tom Leonhardt | idw - Informationsdienst Wissenschaft
Further information:
http://www.uni-halle.de

More articles from Physics and Astronomy:

nachricht Astronomers see 'warm' glow of Uranus's rings
21.06.2019 | University of California - Berkeley

nachricht A new force for optical tweezers awakens
19.06.2019 | University of Gothenburg

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fraunhofer IDMT demonstrates its method for acoustic quality inspection at »Sensor+Test 2019« in Nürnberg

From June 25th to 27th 2019, the Fraunhofer Institute for Digital Media Technology IDMT in Ilmenau (Germany) will be presenting a new solution for acoustic quality inspection allowing contact-free, non-destructive testing of manufactured parts and components. The method which has reached Technology Readiness Level 6 already, is currently being successfully tested in practical use together with a number of industrial partners.

Reducing machine downtime, manufacturing defects, and excessive scrap

Im Focus: Successfully Tested in Praxis: Bidirectional Sensor Technology Optimizes Laser Material Deposition

The quality of additively manufactured components depends not only on the manufacturing process, but also on the inline process control. The process control ensures a reliable coating process because it detects deviations from the target geometry immediately. At LASER World of PHOTONICS 2019, the Fraunhofer Institute for Laser Technology ILT will be demonstrating how well bi-directional sensor technology can already be used for Laser Material Deposition (LMD) in combination with commercial optics at booth A2.431.

Fraunhofer ILT has been developing optical sensor technology specifically for production measurement technology for around 10 years. In particular, its »bd-1«...

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

For a better climate in the cities: Start-up develops maintenance-free, evergreen moss façades

25.06.2019 | Architecture and Construction

An ion channel with a doorkeeper: The pH of calcium ions controls ion channel opening

25.06.2019 | Life Sciences

Cooling with the sun

25.06.2019 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>