A self-driving lab for discovering tunable and soluble organic lasers

We have recently demonstrated the ability of using self-driving laboratories for AI-driven searches of new emitters for organic solid-state lasing devices. Our past workflow featured solubility challenges for such large molecular moieties. In this next-generation study, we returned to the drawing board to explore a family of compounds that were much solution processable and composed of a set of electronic cores that would give a broader color response. Out of 252 potential candidates, we selectively performed a comprehensive study exploring 52 fluorene-based A-B-A type organic laser oligomers, armed with our self-driving lab. The candidates ranged from simple hydrocarbon molecules to complex hetero atom-mixed molecules. As a result of this study, we highlight diketopyrrolopyrrole and benzodiazole derivatives for largely red-shifted emissions. Furthermore, we investigated the effect of color change from hetero atom permutation, fluorine addition, thiophene coupling, and a combination of fluorine addition and thiophene coupling. The computational study with density functional theory and natural transition orbital method confirmed the experimental results.