Surface-Order Mediated Assembly of 蟺-Conjugated Molecules on Self-Assembled Monolayers with Controlled Grain Structures

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• 作者：Boseok Kang ; Namwoo Park ; Jeonghwi Lee ; Honggi Min ; Hyun Ho Choi ; Hwa Sung Lee ; Kilwon Cho
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：July 14, 2015
• 年：2015
• 卷：27
• 期：13
• 页码：4669-4676
• 全文大小：583K
• ISSN：1520-5002

文摘

This study systematically demonstrates the effects of the grain structure of crystalline self-assembled monolayers (SAMs) on the growth of organic semiconductor thin films on such monolayers, as well as the electrical characteristics of the resulting semiconductor films. The grain structure of the octadecyltrichlorosilane (OTS) monolayers could be tailored by constructing the monolayers at three different temperatures: 鈭?0 掳C (鈭?0 掳C OTS), 鈭? 掳C (鈭? 掳C OTS), and 20 掳C (20 掳C OTS). Among the three layers, 鈭?0 掳C OTS exhibited the largest crystalline grains and longest-range homogeneity of alkyl chain arrays. We found that pentacene films deposited on 鈭?0 掳C OTS monolayers show larger crystalline grains with higher degrees of crystallinity and lateral alignment compared to that of films deposited on 鈭? 掳C OTS or 20 掳C OTS monolayers, following the surface characteristics of the underlying OTS monolayers. Furthermore, pentacene field-effect transistors fabricated with 鈭?0 掳C OTS monolayers showed lower charge trap densities and higher field-effect mobility values than devices fabricated using 鈭? or 20 掳C OTS monolayers. These results are explained in terms of enhanced quasi-epitaxial growth of pentacene films on OTS monolayers with large grains.