Fig. 6: Identification of key polymer units by using a SHAP evaluation.

a The generation strategy of PUFp. b–e The interpretations of the ML models for P-type, N-type, P-N classification and D-A polymer-unit interaction of N-type by the SHAP evaluation. The blue and red bars on the right denote the proportional relation between the units and the prediction values. f–i Chemical structures of the PUs and their roles are identified through the importance analysis.