Organic Semiconducting Alloys with Tunable Energy Levels

Continuous band structure tuning, e.g. doping with different atoms, is one of the most important feature for inorganic semiconductors. How-ever, this can hardly be realized in organic semicondutors. Here we report the first example of fine tuning organic semiconductors band structures by alloying structurally similar derivatives into one single phase. By incorporating halogen atoms on different positions of the backbone, BDOPV derivatives with complementary intramolecular or intermolecular charge distribution were obtained. To maximize the Coloumbic attractive interactions and minimize repulsive interactions, they form antiparallel cofacial stacking in monocomponent or in alloy single crystals, resulting in efficient π orbital overlap. Benefiting from self-assembly induced solid state “olefin metathesis” reaction, it was observed, for the first time, that three BDOPV derivatives co-crystallized in one single crystal. Molecules with different energy levels serve like the dopants in in-organic semiconductor...