We investigated tetracyanoanthracenediacenaphthalimides (TCDADIs) as n-type organic semiconductors (OSCs) and assessed their molecular self-assembly in forming monolayers and thin films using optical absorption spectroscopy, scanning tunneling microscopy (STM), atomic force microscopy (AFM), and grazing incidence wide-angle X-ray scattering (GIWAXS). The absorption spectra, along with quantitative GIWAXS analysis, reveal the influence of molecular structure (alkyl chain length) and film processing conditions (annealing temperature and spin-coating speed) on the orientation of TCDADI molecules in films. Our findings indicate that increasing the spin-coating speed and annealing temperatures causes a transition from a mixed phase to a predominantly edge-on molecular orientation. This transition significantly enhances the electron mobility, from 0.01 to 0.05 cm² V^–1 s^–1 for TCDADI-C16 and from 0.13 to 0.20 cm² V^–1 s^–1 for TCDADI-C24. In addition, we highlight the potential of TCDADIs for photodetector applications, showing a photoresponse gain of over 2000 under white light.

中文翻译：

---

四氰基蒽二邻苯二胺作为 n 型有机半导体：分子取向的控制


我们研究了作为 n 型有机半导体 （OSC） 的四氰基蒽二邻苯二胺 （TCDADIs），并使用光吸收光谱、扫描隧道显微镜 （STM）、原子力显微镜 （AFM） 和掠入射广角 X 射线散射 （GIWAXS） 评估了它们在形成单层和薄膜中的分子自组装。吸收光谱以及定量 GIWAXS 分析揭示了分子结构（烷基链长度）和薄膜加工条件（退火温度和旋涂速度）对薄膜中 TCDADI 分子取向的影响。我们的研究结果表明，提高旋涂速度和退火温度会导致从混合相转变为主要边缘的分子取向。这种转变显著提高了电子迁移率，TCDADI-C16 的电子迁移率从 0.01 到 0.05 cm² V^–1 s^{–1，TCDADI-C24} 的电子迁移率从 0.13 cm 2 V^–1 s–1 提高到 0.20 cm² V–1 s^–1。此外，我们强调了 TCDADI 在光电探测器应用中的潜力，在白光下显示光响应增益超过 2000。