Suppressing Energetic Disorder of Organic Semiconductors for Semitransparent Photovoltaics and Thin‐Film Transistors

The weak intermolecular interaction and short-range aggregation endow organic semiconductors with the merits of flexibility, light weight, and solution processibility, while introducing more disorders at the same time. The greater degree of disorders in organic semiconductors, compared to inorganic semiconductors, is one of the major obstacles to their performance; thus, minimizing disorders is a key approach to boost the performance of organic electronics. Here, a strategy of using phthalate esters is introduced as assembly-inducing agents (AIAs) to improve the packing ordering of organic semiconductors, thereby reducing the energetic disorders and improving the device performance. With dioctyl phthalate AIA, the organic semiconductor PM6 shows a 24% reduction in Urbach energy, 11% narrower absorption full width at half maximum, and suppressed absorption tails in thin film. In organic field-effect transistors, this strategy offers a lift of hole mobility by 33.3%. In semitransparent organic photovoltaics, this strategy improves the average visible transmittance by 11.2% while maintaining the power conversion efficiency, yielding a high light utilization efficiency of 4.63% in optical structure-free devices. This work provides a facile and effective approach to suppress the energetic disorder of organic semiconductors and opens up a new avenue for fabricating high-performance organic electronics.