Chemical-Conversion-Mediated Growth of Organic Structures in Solution System and Their Enhanced Optical and Electrical Properties

Abstract

Over the past few decades, there has been an increasing interest in the next-generation electrical devices to achieve better performance and portability than previous silicon-based electronics, and researchers have developed novel materials that can be applied in such applications. Organic materials are one of these candidates, and one of their major strong points is that their constituting elements, such as carbon and hydrogen, are abundant and economic unlike their inorganic counterparts. Also, their superior flexibility like polymers have shown that these materials are optimal choices for flexible, transparent electronics. Their innate low performance because of low charge carrier mobility, for instance, have triggered in-depth studies on the development of well-defined crystalline or interface of organic molecules to improve their performances without defects and complex molecular modification. However, most organic materials have not been grown into such well-defined crystals, because conventional growth methods usually require high solubility in solvents or strong thermal stability, all of which are not very common in organic molecules. Herein, we propose a novel “chemical conversion method” to grow single crystals and uniform interfaces made of these organic molecules that have not been compatible with conventional growth method. This method combines the synthesis of organic molecules by well-known chemical reactions of precursors and the subsequent growth of organic structures out of these as-synthesized molecules. As a proof of concept, we plan to synthesize 1) single crystals of 6,13-pentacenequinone from pentacene bulk powder with o-xylene and other organic solvents and 2) DPPH/DPPH2 core/shell wires with uniform interfaces from DPPH single crystals using ascorbic acid. These examples, to the best of our knowledge, could not be prepared by conventional growth methods. In addition, we plan to demonstrate the improvement of optical and electrical properties of each structure with respect to the original precursors.demonstrate the improvement of optical properties and electrical properties of each structure with respect to the original precursors.