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

Abstract

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 mm . 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.

Precise Patterning of Organic Semiconductor Crystals for Integrated Device Applications

“…Recently, the surface microstructure–assisted patterning method was also extended for the formation of patterned 0D organic crystals. Zhang et al reported an alternating‐electric field (AEF)‐based method, which is schematically shown in Figure a. Aqueous dispersion of organic crystals was injected into a tilted cell, which consisted of two parallel pieces of conductive indium–tin oxide (ITO) glasses.…”

“…g,h) SEM images of the 0D and 1D organic crystal–based device arrays. Reproduced with permission . Copyright 2017, Wiley‐VCH.…”

Uniform and Reliable Dip-Coated Conjugated Polymers for Organic Transistors as Obtained by Solvent Vapor Annealing

“…Solution-processed organic field-effect transistors (OFETs) have received considerable attention because of their attractive features of superior intrinsic mechanical flexibility, dramatic performance improvement, and compatibility with low-cost printing processes. − These fascinating features of OFETs make them ideal candidates for applications such as flexible display backplanes, sensors, radio frequency identification tags, smart memory, and wearable electronic systems. − Over the past few decades, apart from developing high-mobility organic semiconductors, researchers have focused on developing low-cost solution-based processes for OFETs using various printing techniques (e.g., doctor-blade coating, bar coating, inkjet printing, and dip-coating). − These techniques have been optimized to yield polymer thin films with uniform and smooth morphologies and desirable crystal structures that ensure efficient charge transport in OFETs. ,− …”

Vapor-solid interfacial reaction and polymerization for wafer-scale uniform and ultrathin two-dimensional organic films

“…In the first type, the driving force for organizing materials arises mainly from π-π van der Waals interactions among conjugated organic molecules. The second type takes advantage of both π-π and external interactions, such as mechanical forces [15] and capillary force [16]. The former is governed in the case of physical vapor deposition.…”