Giant Growth of Crystalline Films of 1,3,5-Tris(N-carbazolyl)benzene (TCB) and 1,3,5-Tris(diphenylamino)benzene (TDAB) on Engineered Shapes of Ionic Liquid in Vacuum

• Type: Article in International Scientific Journal
• Date: 2025

Authors

Farinha, AFM (Author) Other; Oliveira, GNP (Author) Other; araujo, j. p. (Author) FCUP; Luis M N B F Santos (Author) FCUP; Costa, JCS (Author) FCUP

Journal

Title: Crystal Growth & Design

Vol. 25

Pages: 612-623

ISSN: 1528-7483

Publisher: American Chemical Society

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Other information

Authenticus ID: P-017-Z34

DOI: 10.1021/acs.cgd.4c01355

Abstract (EN): This study demonstrates the efficacy of ionic liquid (IL)-assisted vapor deposition in achieving high-quality and distinctive crystal film growth of two organic semiconductors (OSCs): a carbazole derivative (TCB) and a phenylamine derivative (TDAB). ILs with different wetting properties (short-chain [C2C1im][NTf2] and long-chain [C8C1im][NTf2]) and engineered shapes (microdroplets and coalesced film) were utilized as solvents in a vacuum. Through a meticulously designed experimental strategy, encompassing both sequential and simultaneous deposition of the IL and the OSC, this study unveils the pivotal role of ILs in shaping the crystallization behavior of the organic compound. Differential scanning calorimetry, polarized light microscopy, high-resolution scanning electron microscopy, and X-ray diffraction were employed for the films' thermal, morphological, and structural characterization. Thin films of TDAB exhibit crystallinity and a greater tendency to grow tridimensionally, forming giant pillars. However, the typical vertical growth of TDAB on solid substrates is altered when deposition occurs on surfaces coated with ILs. The IL promotes the lateral growth of nanostructures. The experimental results reveal variations in film morphology and coverage influenced by the cation alkyl chain length of the IL. In contrast to TDAB, TCB films are amorphous when thermally evaporated on solid substrates. Notably, IL-assisted vapor deposition induces the crystallization of TCB. Furthermore, TCB films deposited on coalesced IL films exhibit enhanced crystallinity and homogeneous horizontal growth, representing a significant finding in the context of thin film deposition and semiconductor device fabrication.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12