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Abstract Solution‐processable organic semiconductors can serve as the basis for new products including rollable displays, tattoo‐like smart bandages for real‐time health monitoring, and conformable electronics integrated into clothing or even implanted in the human body. For such exciting commercial applications to become a reality, good device performance and uniformity over large areas are necessary. The design of new materials has progressed at an astonishing pace, but accessing their intrinsic, efficient electrical properties in large‐area flexible device arrays is difficult. The development of protocols that allow integration with industrial‐scale processing for high‐throughput manufacturing, without the need to compromise on performance, is the key for transitioning these materials to real‐life applications. In this work, large‐area arrays of organic thin‐film transistors obtained by spray‐coating the high‐mobility polymer indacenodithiophene‐co‐benzothiadiazole (IDTBT) are demonstrated. A maximum charge carrier mobility of 2.3 cm²V⁻¹s⁻¹, with a very narrow performance distribution, is obtained over surface areas of 10 cm × 10 cm. The devices retain their electrical properties when bent multiple times and at different curvatures. In addition, large arrays of highly sensitive (0.25% change in mobility for 1% humidity variation), reusable, near‐identical humidity sensors are produced in a one‐step fabrication and calibrated from 0% to 94% relative humidity. 

The weak intermolecular interactions inherent in organic semiconductors make them susceptible to defect formation, resulting in localized states in the band-gap that can trap charge carriers at different timescales. Charge carrier trapping is thus ubiquitous in organic semiconductors and can have a profound impact on their performance when incorporated into optoelectronic devices. This review provides a comprehensive overview on the phenomenon of charge carrier trapping in organic semiconductors, with emphasis on the underlying physical processes and its impact on device operation. We first define the concept of charge carrier trap, then outline and categorize different origins of traps. Next, we discuss their impact on the mechanism of charge transport and the performance of electronic devices. Progress in the filed in terms of characterization and detection of charge carrier traps is reviewed together with insights on future direction of research. Finally, a discussion on the exploitation of traps in memory and sensing applications is provided.