Contact line curvature-induced molecular misorientation of a surface energy patterned organic semiconductor in meniscus-guided coating

Abstract

The printing of organic semiconductors (OSCs) by means of meniscus guided coating (MGC) has great potential for the fabrication of high-performance, uniform, and large area flexible electronics. Furthermore, surface energy patterning allows low-cost, large area manufacturing, and is a requirement for device isolation to achieve accurate drive and to minimize power consumption. We investigated the morphological and electrical characteristics of surface energy patterned OSCs coated using the MGC method. A unique phenomenon, contact line curvature-induced molecular misorientation effect, which occurs in the patterning of OSCs with the MGC method, is demonstrated. This effect is highly dependent on the pattern width which decided contact line curvature. It influences the charge transport properties and hence the field-effect mobility of organic thin-film transistors (OTFTs). OTFTs in widths ranging from 50 to 500 µm were fabricated. The highest misorientation angle was induced in the 50 µm pattern width and the corresponding OTFTs exhibited the highest mobility. Cover Manuscript Click here to view linked References

Facile Direct Printing of DPP-Based Polymers for Organic Field-Effect Transistors and Logic Gates

“…The line printing of the P29DPP-TT led to partial isolation of the semiconductor layer which can result in reduced leakage current. 33,41 The EHD printing at 10 mm s −1 having a more favorable morphology with less randomness compared to those of printing at 5 and 15 mm s −1 increased the μ FET value.…”

“…This result implies that the line patterning and enhanced polymer aggregation of EHD-printed polymer films brought higher μ FET values compared to those of spin-coated samples, although the randomness of orientation and d -spacing values increased in EHD-printed films. The line printing of the P29DPP-TT led to partial isolation of the semiconductor layer which can result in reduced leakage current. , The EHD printing at 10 mm s –1 having a more favorable morphology with less randomness compared to those of printing at 5 and 15 mm s –1 increased the μ FET value.…”

Nanocrystal Array Engineering and Optoelectronic Applications of Organic Small-Molecule Semiconductors

“…The channel-restricted meniscus self-assembly strategy [ 49 ] solves the problem where the traditional solution method leads to the heterogeneous nucleation behavior and aggregation of polycrystalline molecules during crystal growth. PR channels were used to pattern the substrate at both micro- and nano-scales to constrain the meniscus [ 50 , 51 , 52 , 53 ], thereby reducing the size of the anterior meniscus. In Figure 15 a, when the PR channel is immersed in organic solution, a meniscus contour contact line is formed between two adjacent PR fringes.…”

Tailoring the molecular weight of polymer additives for organic semiconductors

“…First, when drop casted in solution, TIPS pentacene forms dendritic patterns of crystal ribbons, which can be characterized by considerable crystal misorientation and film gaps [87][88][89][90][91][92][93][94][95][96][97][98]. In a pivotal study conducted by Chen and coworkers [99], the misorientation angle θ was measured between the TIPS pentacene crystal long axis and the direction from source to drain contact electrodes in the transistor device.…”