Structures, Properties, and Device Applications for [1]Benzothieno[3,2‐b]Benzothiophene Derivatives

[1]benzothieno[3,2-b]benzothiophene (BTBT), with two benzene rings as the outermost rings, is referred to as diacene-fused ladder-type π-conjugated thienothiophenes. During the last three decades, derivatives based on BTBT core have been extensively studied due to their tremendous application prospects in organic field-effect transistors (OFETs) and organic optoelectronic devices. In order to further advance the development of organic electronics, new materials are constantly being synthesized and new methods are constantly evolving. This review mainly focuses on the crystal and electronic structures of BTBT derivatives, the soluble and thermal properties, the fabrication methods, as well as the strategies for performance improvement and optoelectronic applications including OFETs, photodetectors, synaptic devices, and organic light-emitting transistors. As one of the most promising organic materials, the insight into BTBT-based molecules will accelerate their potential application and provide important reference value for the development toward commercialized and industrialized organic semiconducting products.