Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

High-speed surveillance in solar cells catches recombination red-handed

14.02.2019

Researchers at Osaka University introduce a new time-resolved microscopy method that allows them to monitor the trajectories of fast-moving charged particles at unprecedented rates

A research team at Osaka University has developed an improved method for producing microscope images that can spot speedy electrons zipping through nanomaterials used in solar panels.


This is a schematic diagram illustrating the principle of tip-synchronized time-resolved electrostatic force microscopy.

Credit: Osaka University

By applying laser light to the device at just the right times, this group achieved nanosecond time resolution for the first time while maintaining the magnification. This work could improve the quality of photovoltaic materials for devices such as solar panels by helping to identify and eliminate inefficiencies during the manufacturing process.

Surveillance cameras are ubiquitous, and extremely valuable to the police when trying to catch thieves. However, cameras that record only a single movie frame per minute would be useless for apprehending speedy robbers who can make their getaway in less than sixty seconds.

Solar panels harness the power of the sun when electrons become excited to a higher energy level, leaving a void, or "hole", behind. However, if an electron recombines with a hole before reaching the electrode, the harvested energy is lost, "robbing" the device of critical efficiency.

Currently available microscopy methods are too slow to catch the miscreants in the act. So the team at Osaka used electrostatic force microscopy (EFM), in which a tiny, vibrating cantilever tip is made sensitive to electric charges passing beneath it.

EFM is still usually too slow to watch electrons and holes in motion, but their key innovation was to apply synchronized laser pulses that hit the sample at the same point of the cantilever's oscillation. By altering the delay time between the start of the cycle and the laser pulse, they were able to create a movie with frames as fast as 300 nanoseconds. "This is the first time anyone was able to combine nanosecond time resolution without sacrificing magnification," said lead author Kento Araki.

When the researchers probed the "scene of the crime", they were able to obtain video evidence of recombination as it was occurring. This method may be extremely useful for designing more efficient solar panels by reducing the energy losses due to recombination. According to senior author Takuya Matsumoto, "the research is also potentially useful for the study of catalysts or batteries that depend on light activation."

###

The article, "Time-resolved electrostatic force microscopy using tip-synchronized charge generation with pulsed laser excitation" was published in Communications Physics at DOI: https://doi.org/10.1038/s42005-019-0108-x.

About Osaka University

Osaka University was founded in 1931 as one of the seven imperial universities of Japan and now has expanded to one of Japan's leading comprehensive universities. The University has now embarked on open research revolution from a position as Japan's most innovative university and among the most innovative institutions in the world according to Reuters 2015 Top 100 Innovative Universities and the Nature Index Innovation 2017. The university's ability to innovate from the stage of fundamental research through the creation of useful technology with economic impact stems from its broad disciplinary spectrum. Website: https://resou.osaka-u.ac.jp/en/top

Saori Obayashi | EurekAlert!
Further information:
https://resou.osaka-u.ac.jp/en/research/2019/20190130_1
http://dx.doi.org/10.1038/s42005-019-0108-x

More articles from Power and Electrical Engineering:

nachricht Efficient, Economical and Aesthetic: Researchers Build Electrodes from Leaves
03.07.2020 | Leibniz-Institut für Photonische Technologien e. V.

nachricht Electrons in the fast lane
03.07.2020 | Max-Planck-Institut für Polymerforschung

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

Im Focus: ILA Goes Digital – Automation & Production Technology for Adaptable Aircraft Production

Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...

Im Focus: AI monitoring of laser welding processes - X-ray vision and eavesdropping ensure quality

With an X-ray experiment at the European Synchrotron ESRF in Grenoble (France), Empa researchers were able to demonstrate how well their real-time acoustic monitoring of laser weld seams works. With almost 90 percent reliability, they detected the formation of unwanted pores that impair the quality of weld seams. Thanks to a special evaluation method based on artificial intelligence (AI), the detection process is completed in just 70 milliseconds.

Laser welding is a process suitable for joining metals and thermoplastics. It has become particularly well established in highly automated production, for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

 
Latest News

Rising water temperatures could endanger the mating of many fish species

03.07.2020 | Life Sciences

Risk of infection with COVID-19 from singing: First results of aerosol study with the Bavarian Radio Chorus

03.07.2020 | Studies and Analyses

Efficient, Economical and Aesthetic: Researchers Build Electrodes from Leaves

03.07.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>