Science & Technology

Robots develop new semiconductor materials in tests that are 10 times faster & greener

With the technology, scientists have been able to develop alloys with perovskites materials that can improve solar cells

 
By Preetha Banerjee
Published: Wednesday 26 July 2023
RoboMapper, the new technology, has already identified perovskite materials used in solar cells that have more stability and efficiency. Photo for representation only. Source: iStock_

Scientists have created a robot that can do material testing in a more efficient and sustainable manner, according to a new report published in the journal Matter.

In much shorter time than it would take scientists, RoboMapper, the new technology, has already identified perovskite materials used in solar cells that have more stability and efficiency.

The researchers gave the robot a set of materials and asked it to develop alloys with the same. It came up with 150 different compositions and ran various tests on them to understand the following things:'

  • Whether it had the crystalline structure of a perovskite
  • Whether it had a desirable set of optical characteristics, known as the band gap
  • Whether it was stable when exposed to intense light

The data was used to build a computational model “that identified a specific alloy composition that it predicted would have the best combination of desired attributes”.

“RoboMapper allows us to conduct materials testing more quickly, while also reducing both cost and energy overhead – making the entire process more sustainable,” said Aram Amassian, corresponding author of a paper on the work and a professor of materials science and engineering at North Carolina State University.

The conventional process is much longer and energy-consuming. A scientist has to prepare a sample and test each of them individually using multiple instruments. This involves placing, aligning and calibrating samples as needed to collect the data, according to the authors of the report.  

“The material we identified using RoboMapper also turned out to be more efficient at converting light into electricity in solar cell devices,” Amassian observed. 

Previous efforts made the process a little quicker, “but each of the steps still had to be done with one sample at a time”. Most of the tech would have a sample per chip moving through the entire data collection process.

“RoboMapper also automates this process, but places dozens of samples on each chip by miniaturising the material samples with the help of modern printing,” Amassian said. “It still performs each step of the data collection process, but it does so for multiple materials in parallel, saving time and energy.”

The new, more sustainable method is nearly 10 times faster than previous automated techniques, said Tonghui Wang, lead author of the paper and a PhD student at NC State University.

The process also reduced greenhouse gas emissions of the characterisation process by 10 times, the authors noted.

Using the tech, scientists already made great strides in overcoming a major challenge in improving solar cells: How to make them with perovskites. The material is desirable because it can absorb sunlight better than silicon, which means the cells can be lighter. But its stability has been a challenge as it degrades on exposure to light and are stripped of its valuable properties. 

Going forward, the scientists want to expand the range of potential alloys for testing to be used in photovoltaic cells and other devices. 

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