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 recy- clable 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 mo- lecular design of organic semiconductors, as well as a state-of-the-art nanocrystalline films with eco-friendly pro- cedures. Then, we highlighted the progress on SFX-based organic semiconductors in the organic light-emitting di- ode （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.