A collaborative research team led by Professor Li Yuan from South China University of Technology(SCUT), in partnership with the Changchun Institute of Applied Chemistry of the Chinese Academy ofSciences, the University of Science and Technology of China, and LONGi Green Energy TechnologyCo., Ltd., has published a paper in Science titled 'Stable and Uniform Self-assembled Organic DiradicalMolecules for Perovskite Photovoltaics.' This study disclosed the open-shell 'quinoid-diradical' electronspin ground state of the 'donor-acceptor' self-assembled monolayer (SAM) material and elucidatedthe 'structure-property' relationship between molecular conductivity and their 'open-shell-diradical'electronic spin ground state.

Figure 1：The Chichibabin radical since 1907 and the 'quinoid-diradical' proposed by Li Yuan's team in2017

In 2017, Professor Li Yuan's team published a paper titled 'A Review on the Origin of Synthetic MetalRadical: Singlet Open-shell Radical Ground State?' in The Journal of Physical Chemistry C theAmerican Chemical Society (Fig. 1: J. Phys. Chem. C 2017, 121, 15, 8579-8588), in which Professor YuanLi boldly and imaginatively reviewed the 'closed-shell-singlet ground state' of classic 'donor-acceptor'organic semiconductors. The current research findings further validate the open-shell 'quinoiddiradical' electron spin ground state and the 'aggregation-induced radical' mechanism initiallyproposed by Yuan Li's team in 2017. This work provides an example of industry-academia-researchcollaboration in the application of 'donor-acceptor' diradical materials and demonstrates theapplication potential of organic 'donor-acceptor' diradicals.

Figure 2. Design strategy for the "donor-acceptor" diradical self-assembled molecules and theircorresponding electron spin resonance spectra.