Heterogeneous Monolithic Integration of Single‐Crystal Organic Materials

Abstract

Manufacturing high-performance organic electronic circuits requires the effective heterogeneous integration of different nanoscale organic materials with uniform morphology and high crystallinity in a desired arrangement. In particular, the development of high-performance organic electronic and optoelectronic devices relies on high-quality single crystals that show optimal intrinsic charge-transport properties and electrical performance. Moreover, the heterogeneous integration of organic materials on a single substrate in a monolithic way is highly demanded for the production of fundamental organic electronic components as well as complex integrated circuits. Many of the various methods that have been designed to pattern multiple heterogeneous organic materials on a substrate and the heterogeneous integration of organic single crystals with their crystal growth are described here. Critical issues that have been encountered in the development of high-performance organic integrated electronics are also addressed.

Insights into the Control of Optoelectronic Properties in Mixed‐Stacking Charge‐Transfer Complexes

“…Micro/nanocrystals suitable for device fabrication were prepared through drop casting the mixed solution onto the substrate, whereby TMIQ and co‐formers recognize and self‐assemble in an orderly way (long ribbons) through noncovalent interactions, as in bulk molecular cocrystals, which are different from the single‐component crystals under the same conditions (Figure S13 and S14 in the Supporting Information).The XRD patterns of these as‐formed micro/nanocrystals demonstrate that D and A molecules are alternately packed into microribbons with the long edge (conduction direction) along the mixed‐stacking direction ( b axis for TMFA, b axis for TMCA, and a axis for TMTQ; Figure b, e, and h), which provides a perfect platform to investigate the regulation of the optoelectronic properties. It has long been a major challenge to pattern and precisely register organic semiconductors in the transistor channel region over a large area, which is crucial in a bottom‐up strategy . Solvent wetting/dewetting surface treatment has been reported to be an efficient route to achieve the precise positioning and patterning of crystals, owing to a dewetted surface with poor affinity to organic solvents and wetted surface with good affinity.…”

“…It has long been am ajor challenge to pattern and precisely register organic semiconductors in the transistor channel region over a large area, which is crucial in ab ottom-up strategy. [37,38] Solvent wetting/dewetting surface treatment has been reported to be an efficient route to achieve the precise positioning and patterning of crystals, [39][40][41][42] owing to ad ewetted surfacew ith poor affinity to organic solvents and wetted surface with good affinity.O nt his basis, we explored af acile and economical methodt op attern bottom-contact (BC) OFETsw ith cocrystal arrays, asd epicted in Figure 4a,b ecause the crystal is barely selectively nucleated and self-assembled on the wettede lectrodes.T hus, this methodc an allow us to precisely registert he crystalline domains across the channel regions when the satisfying conditions of W and L (see detailsi nt he Supporting Information)a re met.…”

2D Organic Materials for Optoelectronic Applications

“…Furthermore, long‐range order and defect‐free 2D crystals are seen as an ideal system for high‐performance devices and circuits, and large‐area 2D crystals seem to have a bright future in industrial applications. However, the preparation of 2D molecular crystals faces many challenges, such as the polycrystalline nature of prepared films, their limited lateral dimensions, and their relative thickness of tens or hundreds of nanometers . Many molecules and techniques have been designed and developed to realize the 2D advantages of large size (e.g., millimeter size), mono‐ or a few molecular layers, and high crystalline quality.…”

“…Patterned arrays of organic crystals are indispensable for large‐scale, high performance, and high integration organic circuits because they can effectively reduce gate leakage current and minimize crosstalk between adjacent devices . However, organic crystals are vulnerable to high temperature and the organic solvent, which result in an incompatibility with conventional top‐down photolithography techniques that involve multiple step solvent processing.…”

Unconventional Nanofabrication for Supramolecular Electronics

“…This unique hollow structure could get rid of physical barriers to the growth of crystalline domains and highly beneficial to connect adjacent regions to realize a large-area self-suspended nanomesh electrode. [148,149] Figure 9b i shows the picture of bent self-supported nanomesh scaffold devices on PET substrate, after 1000 times bending fatigue test the photoresponsivity slightly reduced to 79% of its initial performance, but the structural strength of hollow nanomesh scaffold was solid enough to maintain a ultralow leakage current through the whole bending test (Figure 9b, ii and iii). (Figure 9c, ii).…”