Precise Patterning of Organic Single Crystals via Capillary‐Assisted Alternating‐Electric Field

Owing to the extraordinary properties, organic micro/nanocrystals are important building blocks for future low‐cost and high‐performance organic electronic devices. However, integrated device application of the organic micro/nanocrystals is hampered by the difficulty in high‐throughput, high‐precision patterning of the micro/nanocrystals. In this study, the authors demonstrate, for the first time, a facile capillary‐assisted alternating‐electric field method for the large‐scale assembling and patterning of both 0D and 1D organic crystals. These crystals can be precisely patterned at the photolithography defined holes/channels at the substrate with the yield up to 95% in 1 mm². The mechanism of assembly kinetics is systematically studied by the electric field distribution simulation and experimental investigations. By using the strategy, various organic micro/nanocrystal patterns are obtained by simply altering the geometries of the photoresist patterns on substrates. Moreover, ultraviolet photodetectors based on the patterned Alq3 micro/nanocrystals exhibit visible–blind photoresponse with high sensitivity as well as excellent stability and reproducibility. This work paves the way toward high‐integration, high‐performance organic electronic, and optoelectronic devices from the organic micro/nanocrystals.