Large‐Area Deposition of Highly Crystalline F4‐Tetracyanoquinodimethane Thin Films by Molecular Step Templates

Abstract

Theoretical studies have unequivocally determined the exceptional electron transport properties of the fluorinated tetracyanoquinodimethane (Fx‐TCNQ) family, presenting a promising avenue for the realization of high‐performance n‐channel organic thin‐film transistors (OTFTs). However, owing to the intrinsic low crystallinity of this class of materials, Fx‐TCNQ‐based n‐channel OTFTs have not been experimentally achieved so far. Herein, a molecular step template (MST)‐assisted method that dramatically improves the crystallinity of F4‐TCNQ thin films is reported. The MST not only lowers the nucleation barrier of F4‐TCNQ molecules along the in‐plane direction but also reduces the nucleation density. This approach facilitates the realization of compact, oriented, and highly crystalline F4‐TCNQ thin films, resulting in impressive electron mobility of up to 2.58 cm2 V−1 s−1. Notably, this achievement surpasses the electron mobility of F4‐TCNQ thin films fabricated without the MST by a factor of 107. Furthermore, the incorporation of the p‐type MST provides a novel pathway for constructing complementary inverters, showcasing a high voltage gain of 112.6 V V−1 and a substantial noise margin of 89.3% with exceptional uniformity. In this work, a general and efficient route is paved to produce high‐performance n‐channel OTFTs toward organic complementary circuits.

Keywords

• crystalline organic thin films
• fluorinated tetracyanoquinodimethane
• n‐channel organic semiconductors
• organic complementary inverters
• organic thin‐film transistors