Researchers at the North Carolina State University have developed RoboMapper, a robot designed to identify new perovskite materials with enhanced stability and solar cell efficiency.

While perovskite materials are being studied as the potential substitute for the largely used silicon, perovskite tend to degrade when exposed to continuous intense sunlight. With an aim to maintain the stability in perovskite materials, the researchers, through their new work, enabled RoboMapper to perform experiments that could yield a range of new semiconductor materials.

The researchers designed their robot to make alloys using specific elements and conducted tests to identify whether an alloy was suitable for tandem solar cells.

The study titled ‘Sustainable Materials Acceleration Platform Reveals Stable and Efficient Wide Bandgap Metal Halide Perovskite Alloys’ was published in the journal Matter.

The researchers were looking to determine whether the alloy comes with a crystalline structure similar to that of a perovskite material and if it had a bandgap. The robot also performed experiments to understand the degradation level of the alloy when exposed to intense light.

Based on the encoded instructions, RoboMapper created samples of 150 varying alloy compositions and then conducted optical spectroscopy and X-ray structural assessments on these samples.

Using the data collected during these experiments, the researchers developed a computational model to derive a particular alloy composition that they claimed to be the best combination of desired attributes.

Aram Amassian, corresponding author of the paper and a professor of Materials Science and Engineering at North Carolina State University, said, “The material we identified using RoboMapper turned out to be more efficient at converting light into electricity in solar cell devices. Our conventional techniques validated the results from RoboMapper. The robot also automates the process but places dozens of samples on each chip by miniaturizing the material samples with the help of modern printing. It still performs each step of the data collection process but does so for multiple materials in parallel, saving time and energy.”

Environmental economist Lucía Serrano-Luján, co-author of the paper and a researcher at Rey Juan Carlos University and the Technical University of Cartagena, said, the RoboMapper’s ability to streamline the data collection process by placing dozens of materials on the same chip reduced greenhouse gas emissions tenfold.

In another study, scientists at the National Centre for Photovoltaic Research and Education of the Indian Institute of Technology Bombay claimed to have achieved a record power conversion efficiency of over 26% for a 4-terminal silicon-perovskite tandem solar cell.

Earlier this year, researchers at the King Abdullah University of Science and Technology developed a perovskite-silicon tandem solar cell with a record energy conversion efficiency of 33.2%.