Toward Eco-friendly Green Organic Semiconductors: Recent Advances in Spiro[fluorene-9,9′-xanthene] (SFX)-Based Optoelectronic Materials and Devices

Green organic semiconductors (GOS) have the four-element features, including biomass as stuffs, synthesis with the pot, atom and step economic (PASE) route, eco-friendly fabrication processes in aqueous phase, and recyclable devices, capturing the trend of organic electronics in the future. Herein, we reviewed the efforts that have been made on GOS by our group. We first made a brief introduction of organic (opto)electronics, followed by the design strategies of GOSs based on spirofluorenes. Concretely, we described the discovery of one-pot protocol to spirofluorenres and a pot-atom-step economic (PASE) platform of spiro[fluorene-9,9′-xanthene] (SFX) for the molecular design of organic semiconductors, as well as a state-of-the-art nanocrystalline films with eco-friendly procedures. Then, we highlighted the progress on SFX-based organic semiconductors in the organic light-emitting diode (OLED) field. Finally, we conducted a summary on SFXs in OLED and an outlook on green semiconductors starting from biomass, via one-pot to spirofluorenes, to water-phase devices. Spiro[fluorene-9,9′-xanthene] (SFX)-based derivatives with the pot, atom and step-economy (PASE) synthetic route will be a new generation of spirocyclic aromatics to achieve green organic semiconductors.