Near‐Room‐Temperature Solution Epitaxy of Large‐Area High‐Mobility Two‐Dimensional Organic Single Crystals for Direct X‐Ray Detection

ABSTRACT The fundamental trade‐off between high intrinsic carrier mobility and solution processability severely limits the development of organic single crystals (OSCs). For instance, while 2,6‐diphenylanthracene (DPA) is a benchmark candidate for direct X‐ray detection, its intrinsic insolubility hinders solution processing, and conventional solubilizing alkyl modifications inevitably degrade transport efficiency. Here, we report a facile surfactant‐assisted near‐room‐temperature solution epitaxy method to overcome this bottleneck, fabricating centimeter‐scale ultrathin DPA two‐dimensional (2D) OSCs utilizing a common solvent at 35°C. Electrical characterization reveals that the as‐fabricated DPA 2DOSCs exhibit a maximum mobility of 5.55 cm 2 /(V ∙ s), an order of magnitude higher than that of the alkylated C 6 ‐DPA counterpart. This superior charge transport efficiency directly translates into exceptional X‐ray detection performance, achieving a high sensitivity of 7.02 × 10 3 μC/(Gy∙cm 2 ) and a low detection limit of 24.05 nGy/s. This work not only provides a facile low‐energy route to process intrinsically insoluble organic semiconductors but also establishes high‐mobility DPA 2DOSCs as a premier platform for next‐generation large‐area organic direct X‐ray detectors.