Scale Effect of a Fluorescent Waveguide in Organic Micromaterials: A Case Study Based on Coumarin Microfibers

Leveling up Organic Semiconductors with Crystal Twisting

The performance of crystalline organic semiconductors depends on the solid-state structure, especially the orientation of the conjugated components with respect to device platforms. Often, crystals can be engineered by modifying chromophore substituents through synthesis. Meanwhile, dissymetry is necessary for high-tech applications like chiral sensing, optical telecommunications, and data storage. The synthesis of dissymmetric molecules is a labor-intensive exercise that might be undermined because common processing methods offer little control over orientation. Crystal twisting has emerged as a generalizable method for processing organic semiconductors and offers unique advantages, such as patterning of physical and chemical properties and chirality that arises from mesoscale twisting. The precession of crystal orientations can enrich performance because achiral molecules in achiral space groups suddenly become candidates for the aforementioned technologies that require dissymetry.

Efficient Organic Light-Emitting Transistors Based on High-Quality Ambipolar Single Crystals

A cyano-substituted styrene derivative is synthesized and successfully prepared to lamellate single crystals through precisely controlling the crystal growth conditions. The lamellate single crystals with regular edge and smooth surface display intrinsically ordered stacking and high quality, all of which are of importance for high optoelectronic performance. The single-component light-emitting transistors based on the lamellate crystals offer striking device performance in terms of record external quantum efficiency of 2.02%, exceeding the benchmark value in this field. Such organic light-emitting single crystals provide a versatile platform for designing and engineering their structures and optoelectronic properties toward light-emitting devices.