Fabrication of tetrabenzoporphyrin thin-film transistors with hydrogen-bonding networks via a thermal precursor approach and effect of the amide-group position

Abstract

Hydrogen-bonding interactions are a powerful tool for controlling the assembly structures in semiconducting organic thin films. However, their application remains limited, particularly in organic thin-film transistors (OTFTs). Herein, we report new hydrogen-bonding tetrabenzoporphyrin (BP) semiconductor thin films, which were fabricated using a thermal precursor method. This approach involves the formation of a corresponding BP-precursor thin film from a homogenous solution, which is subsequently thermally converted into BP thin films via retro-Diels–Alder reaction. The evaluation of OTFTs revealed relatively high hole-carrier mobilities of the amide-group-functionalized BP derivatives compared to other OTFTs utilizing hydrogen-bonding networks reported to date. The hole mobility was remarkably affected by thin film fabrication conditions, such as the solution concentration and thermal annealing, as well as the inherent molecular crystallinity in the films. This study provides a viable strategy for fabricating hydrogen-bonded semiconducting organic thin films composed of low- or insoluble π-conjugated molecules.