Precisely Patterned Growth of Ultra-Long Single-Crystalline Organic Microwire Arrays for Near-Infrared Photodetectors

摘要

Owing to extraordinary properties, smalt-molecule organic microanocrystals are identified to be prospective system to construct new-generation organic electronic and optoelectronic devices. Alignment and patterning of organic microanocrystals at desired locations are prerequisite for their device applications in practice. Though various methods have been developed to control their directional growth and alignment, high-throughput precise positioning and patterning of the organic microanocrystals at desired locations remains a challenge. Here, we report a photoresist-assisted evaporation method for large-area growth of precisely positioned ultralong methyl-squarylium (MeSq) microwire (MW) arrays. Positions as well as alignment densities of the MWs can be precisely controlled with the aid of the photoresist-template that fabricated by photolithography process. This strategy enables large-scale fabrication of organic MW arrays with nearly the same accuracy, uniformity, and reliability as photolithography. Near-infrared (NIR) photodetectors based on the MeSq MW arrays show excellent photoresponse behavior and are capable of detecting 808 nm light with high stability and reproducibility. The high on/off ratio of 1600 is significantly better than other organic nanostructure-based optical switchers. More importantly, this strategy can be readily extended to other organic molecules,: revealing the great potential of photoresist-assisted evaporation method for future high-performance organic optoelectronic devices.