Low-cost and stable SFX-based semiconductor materials in organic optoelectronics

In the progress of realizing the commercialization of organic optoelectronic materials, the four basic coherent factors are stability, cost, performance, and processability, all which determine the results of device applications. Spiro[fluorene-9,9′-xanthene] (SFX) has been becoming the robust building-block that fulfilling the practical requirements due to its key features of non-planarity, one-pot facile availability, well-defined quality assurance as well as performance behaviors. In this review, we introduce the SFX and its analogues, including synthesis, molecular design, device performance, and structure-property relationship, in the applications of organic light-emitting diodes (OLEDs), organic photovoltaics, perovskite solar cells (PSCs) and others. Furthermore, emitters or hosts for OLED and hole transport materials for PSCs are highlighted at the level of molecular configuration and film morphology. Tracing the thread from intrinsic photoelectric properties, molecular packing to optoelectronic application, the advantage of stability and low-cost of SFX-based materials are illuminated, and an outlook is given providing orientation for bring SFX into the fields of catalysis and energy chemistry in view of its binary conjugation and three-dimensional configuration.