Evidence-grounded large language models guide perovskite solar cell design and optimization
Organizations: School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China. · College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi’an 710021, P. R. China. · Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China.
Abstract
Using large language models to interpret experimental evidence, design discriminating experiments and formulate well-supported mechanistic explanations remains a central challenge in materials research. Here we establish PSM-Bench, an 800-question benchmark developed by perovskite researchers to evaluate scientific reasoning in perovskite photovoltaics. We also introduce OpenPerov, an expert-informed language-model framework that learns from expert-calibrated evidence records reconstructed from 4,035 training articles; these records link experimental strategies, controls and observations to mechanistic interpretations. Structured-evidence adaptation outperformed conventional question-answer training, and OpenPerov Flash ranked first among 13 closed-book systems. OpenPerov Pro raised Scientific Mastery further, from 87.6 to 89.1, by revising selected passages with retrieved evidence. On questions derived from subsequent studies, both models also outscored expert-authored answers. In an experimental test of self-assembled monolayer design, OpenPerov selected a K analogue that outperformed the Na analogue preferred by experts. Devices incorporating the selected contact reached a power conversion efficiency of 27.05% and retained 96.74% of their initial efficiency after 1,000 h of dark thermal ageing at 85 C. These results show that reconstructed scientific reasoning provides an effective basis for building domain models that interpret experiments and inform materials design.
Figures & tables
| Study ID | Article | Journal | Online publication | DOI |
|---|---|---|---|---|
| S20-EC01 | Bypassing the yellow phase for extremely stable formamidinium lead iodide perovskite solar cells | Science | 30 April 2026 | 10.1126/science.aeb7992 |
| S20-EC02 | Stereoelectronic manipulation of ligands for perovskite solar cells | Nature | 13 May 2026 | 10.1038/s41586-026-10626-0 |
| S20-EC03 | Omnidirectional ionic locking network for stable perovskite photovoltaics | Nature Photonics | 29 May 2026 | 10.1038/s41566-026-01918-y |
| S20-EC04 | Perovskite–organic tandem solar cells with a photo-transformable stabilizer | Nature | 13 July 2026 | 10.1038/s41586-026-10869-x |
| S20-EC05 | Controlled solid-state crystallization with formamidinium acetate for fully vacuum-deposited perovskite solar cells | Nature Energy | 14 July 2026 | 10.1038/s41560-026-02093-8 |
| S20-EC06 | An entropy-regulating molecular lock stabilizes formamidinium lead halide perovskite | Science | 14 May 2026 | 10.1126/science.aeb9953 |
| SAM | (V) | (mA cm -2 ) | Fill factor (%) | PCE (%) | |
|---|---|---|---|---|---|
| BCPCz–TMPS–Na | 16 | ||||
| BCPCz–TMPS–K | 16 |
| Order | Leaderboard label | Exact evaluated model or system | Access in this study | Evaluation mode | Architecture | Total parameters | Activated parameters per token |
|---|---|---|---|---|---|---|---|
| 1 | OpenPerov Pro | OpenPerov Flash backbone with evidence retrieval and local revision | Local composite system | Evidence-conditioned | Dense 27B backbone plus retrieval and revision pipeline | 27B backbone | 27B backbone |
| 2 | OpenPerov Flash | OpenPerov Flash, adapted from Qwen3.6-27B | Local weights | Closed-book | Dense | 27B language-model backbone | All backbone parameters (27B) |
| 3 | GLM-5.2 | API identifier: GLM-5.2 | Paratera OpenAI-compatible API; evaluated 24 July 2026 | Closed-book | MoE | 743B a | 39B a |
| 4 | Kimi-K2.6 | API identifier: Kimi-K2.6 | Paratera OpenAI-compatible API; evaluated 24 July 2026 | Closed-book | MoE | 1T | 32B |
| 5 | Qwen 3.7 Max | Provider identifier: Qwen3.7-Max | Paratera OpenAI-compatible API; evaluated 25 July 2026 | Closed-book | Not publicly disclosed | Not publicly disclosed | Not publicly disclosed |
| 6 | Gemini 3.1 Pro | Provider alias: gemini-3.1-pro-preview-maxthinking ; official family: gemini-3.1-pro-preview | Paratera OpenAI-compatible API; evaluated 25 July 2026 | Closed-book | Not publicly disclosed | Not publicly disclosed | Not publicly disclosed |
Large Language Model-Guided Scientific Discovery
Large language model-guided scientific discovery uses AI to propose, test, and refine hypotheses, models, experiments, and designs.
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