Chinese researchers develop high-efficiency perovskite solar cell with enhanced stability

BEIJING -- Researchers from the Institute of Semiconductors under the Chinese Academy of Sciences have achieved a breakthrough in perovskite solar cell technology, paving the way for their commercial adoption, Science and Technology Daily reported on Monday.

The newly developed prototype attained a high photoconversion efficiency of 27.2 percent alongside markedly enhanced operational stability. These findings were recently published in the journal Science.

Producing high-quality perovskite films is crucial for improving solar cell efficiency. While methylammonium chloride is commonly used to assist film growth, the study revealed an issue: during crystallization, chloride ions tend to migrate toward and accumulate near the top surface, resulting in an uneven vertical distribution of chlorine. This inhomogeneity adversely affects both performance and long-term stability.

To address this issue, the team introduced alkali metal oxalate during film formation. The potassium ions released by the oxalate strongly bind to chloride ions, effectively suppressing their uncontrolled migration and promoting a uniform distribution throughout the perovskite layer.

Solar cells fabricated with this optimized film achieved a certified efficiency of 27.2 percent. They also demonstrated excellent stability, retaining 86.3 percent of their initial efficiency after 1,529 hours of continuous operation and 82.8 percent after 1,000 hours under accelerated aging conditions at 85 degrees Celsius with illumination.