Organic Functional Molecule‐Based Single‐Crystalline Nanowires for Optical Waveguides and Their Patterned Crystals

Abstract

The deterministic manufacturing and patterning of high‐quality organic single crystal semiconductors are core opportunities and challenges for large‐scale integrated functional devices with high efficiency and high performance. As for the solution patterning for the fabrication of the organic semiconductors, various methods are reported to efficiently control the position, alignment, and size of organic structures. Nevertheless, the poor control of the dewetting dynamics of organic solution leads to the low crystallinity and disordered crystallographic orientation of as‐fabricated organic architectures, which can limit their device performance. Herein, by use of the micropillar‐structured template with asymmetric wettability, the patterned organic 1D single crystals with precise position and geometry, flat morphology, and high alignment can be constructed. Moreover, the nanowire arrays are demonstrated with active optical waveguiding. In addition, the other patterned architectures of circle, triangle, square, pentagon, and hexagon shapes can also be constituted by regulating the surface geometry of substrates. This work not only facilitates the fundamental understanding on the patterning and crystallization of organic architectures, but also contributes greatly to the development of large‐scale assembly technology for patterning micro/nanostructures.

Recent Advances on Molecular Crystalline Luminescent Materials for Optical Waveguides

“…Reproduced with permission. [43] Copyright 2020, Wiley-VCH. e) Fluorescence images of branched BIDB organic microrods.…”

“…For example, in 2020, Zhang et al reported a method of using micropillar-structured templates with asymmetric wettability to construct patterned OFOW nanowires with precise geometry, high crystallinity, and flat morphology (Figure 5d). [43] The templates with lyophobic tops and lyophilic sidewalls can dominate the dewetting dynamics of a molecule solution and fabricate patterned OFOW precisely by limiting the liquid film in the gaps between the two micropillars and forming capillary tubes with square cross-sections. MFOWs with hetero-/homostructure can be used in optoelectronic circuits, such as optical logic gate function.…”

Construction of Laterally Asymmetric Heterojunctions with Sub‐Micrometer Resolution by Hierarchical Self‐Assembly of Polythiophene Nanofibers

“…[17][18][19][20] As for molecule-based nano-optoelectronics, developing new methodology to make lateral heterostructures is also the prerequisite to realize some promising applications like organic laser, [21,22] field-effect light-emitting transistors, [23,24] flexible photodetectors, and so on. [25][26][27][28] Although delicate patterns of either nanoelectrodes, [29,30] or OSCs, [31][32][33][34][35][36] have been produced via a variety of methods, there still lacks a successful demonstration of organic laterally asymmetric heterojunction with both adjustable structure and key resolution better than 1 µm, i.e., the upper limit of exciton diffusion length in OSCs. [37,38] The major obstacle lies in their incompatibility of OSCs with standard photolithography procedures such as wet etch, dry etch and lift-off, which represent the most powerful and versatile fabrication tools at length scale of micrometers.…”

Naturally and Elastically Bent Organic Polymorphs for Multifunctional Optical Applications

“…Recently, organic crystals have been employed as a promising anisotropic light transducing media for the next-generation optical communication, [38,[42][43][44] especially in nonlinear optical waveguides, chiral information encoded waveguides and heterostructure waveguides. [45][46][47] Particularly, those crystals with plasticity or elasticity were found to have the capability to transduce light information in the highly bent state.…”