Monitoring of Crystallization Process in Solution-Processed Pentacene Thin Films by Chemical Conversion Reactions
Monitoring of Crystallization Process in Solution-Processed Pentacene Thin Films by Chemical Conversion Reactions
复制标题
DOI：
10.1021/acs.jpcc.0c10431
复制
发表时间：
2021-01-11
影响因子：
3.7
通讯作者：
Hasegawa, Takeshi
中科院分区：
文献类型：
--
作者：
Shioya, Nobutaka;Fujiwara, Ryoi;Hasegawa, Takeshi
在其共轭骨架上具有大取代基的可溶液加工有机半导体由于其在大面积电子学中的潜在应用而迅速受到关注。虽然取代基有助于在有机溶剂中的良好溶解性，但它们在薄膜中产生跳跃位点，不利地影响电荷载流子传输。作为替代材料，具有可热裂解官能团的溶剂可溶性前体化合物是有希望的，其可以通过热处理转化成薄膜以产生仅由共轭体系组成的所需材料。这种前体方法实际上应用于各种基于薄膜的器件。然而，薄膜生长的整个过程仍然未被揭示。在本研究中，由热转化前体制备溶液处理的并五苯薄膜，并通过二维X射线衍射（2D-GIXD）和p-偏振多角度入射分辨光谱法（pMAIRS）等尖端分析工具的结合揭示了化学转化反应过程中的结构演变。突出的是，并五苯结晶在热转化膜，这是从一个典型的生长过程中有很大的不同，以逐步的方式。此外，还定量地讨论了并五苯氧化反应对分子排列的影响。这项研究提供了一个基本的示意图薄膜生长的前体方法。
Solution-processable organic semiconductors having bulky substituent groups on the it-conjugated skeleton are rapidly gaining attention for their potential applications to large-area electronics. While the substituent groups contribute to the good solubility in organic solvents, they give rise to hopping sites in a thin film, affecting adversely the charge-carrier transport. As an alternative material, a solvent-soluble precursor compound with thermally cleavable functional groups is promising, which can be converted by heat treatment into a thin film to generate the desired material consisting solely of conjugated systems. This precursor approach is practically applied to various thin-film-based devices. The overall process of the thin film growth, however, remains unrevealed. In the present study, solution-processed pentacene thin films are prepared from a thermally convertible precursor, and the structural evolution during the chemical conversion reaction has been revealed by a combination of cutting-edge analytical tools of two-dimensional X-ray diffraction (2D-GIXD) and p-polarized multiple-angle incidence resolution spectrometry (pMAIRS). The highlight is that pentacene is crystallized in a stepwise manner in the thermally converted films, which is substantially different from a typical growth process. In addition, influences of the oxidation reaction of pentacene on the molecular arrangement are also discussed quantitatively. This study provides a fundamental schematic of thin films grown by the precursor method.