Scientists from Japan’s Gifu University and the Tokyo Institute of Technology have identified a chalcogenide perovskite material with light absorption attributes strong enough to offer the potential for a theoretical maximum conversion efficiency of 38.7% in a silicon perovskite tandem solar cell.
The material – BaZrTiS3 – has a light absorption coefficient exceeding 105cm-1, the highest of all solar cell materials including chalcogenide perovskites such as SrZrS3, BaHfS3 and SrHfS3, the scientists claim.
The Japanese team claim to have observed high stability in the material at up to 600 degrees Celsius and under water immersion. Their findings were published in the paper Extraordinary Strong Band‐Edge Absorption in Distorted Chalcogenide Perovskites, published in Solar RRL.
“As a top-cell material of a chalcogenide perovskite/c-Si tandem solar cell, BaZrS3-based alloys – including Ba(Zr0.95Ti0.05)S3 and BaZr(S0.6Se0.4)3 – have been fabricated,” the paper noted. “Our device simulation shows that 38% efficiency can be reached in a BaZrS3-alloy top cell and a c-Si bottom cell architecture with a thin top cell thickness of 550nm.”