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arXiv · 2601.03058

Charge Transport in Thin-Film Transistors Based on Liquid-Crystalline Phthalocyanines

L. B. Avila·Zuchong Yang·Ilknur Hatice Eryilmaz·Lilian Skokan·Leonardo N Furini·Andreas Ruediger·H. Bock·I. H. Bechtold·E. Orgiu
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Abstract

We investigate a series of liquid-crystalline phthalocyanines (metal-free and Cu, Zn, Ni, Co complexes) by correlating their vibrational signatures with their electronic performance in organic thin-film transistors (OTFTs). Raman spectroscopy reveals metal-dependent distortions of the phthalocyanine macrocycle, reflected in systematic shifts of the C-N-C and M-N vibrational modes. When integrated into OTFTs, all compounds exhibit markedly enhanced current response under ultrahigh vacuum compared to an N2-rich environment, demonstrating that intrinsic charge transport is strongly suppressed by atmospheric species. Temperature-dependent measurements (100-300 K) show clear threshold-voltage shifts driven by deep interface and bulk traps, while all devices display thermally activated mobility with low activation energies (14-20 meV). These results highlight how mesomorphic order, metal coordination, and environmental conditions collectively govern charge transport in liquid-crystalline phthalocyanines, offering design guidelines for their use as orientable semiconducting materials in organic electronics.

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L. B. Avila, Zuchong Yang, Ilknur Hatice Eryilmaz, Lilian Skokan, Leonardo N Furini, Andreas Ruediger, H. Bock, I. H. Bechtold, E. Orgiu. 2026-06-24. Charge Transport in Thin-Film Transistors Based on Liquid-Crystalline Phthalocyanines. https://doi.org/10.1002/cnma.70297

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