Tuning the charge transport properties of dicyanodistyrylbenzene derivatives by the number of fluorine substituents

Abstract

This work describes controlling charge transport properties of organic field-effect transistors (OFETs) with dicyanodistyrylbenzene-based organic semiconductors. Four fluorinated dicyanodistyrylbenzene derivatives (hTF1, hTF2, hTF3, and hTF5) with different degree of fluorination at the phenyl peripheries were synthesized and subjected to OFET devices. It was shown that the fluorination distinctly alters the polarity of charge transfer characteristics from p-type (hTF1), ambipolar (hTF2, hTF5), to n-type (hTF3). Systematic studies on photophysical, electrochemical, structural, and electronic properties revealed the fine tuning of the charge transport properties by the degree of fluorination. While p-type mobility of hTF1 was smaller than 0.01cm2V−1s−1, n-type mobility of hTF3 was as large as 0.7cm2V−1s−1. On the other hand, well-balanced ambipolar mobilities were achieved for both hTF2 and hTF5 (hole and electron mobilities were virtually equal to be 0.07cm2V−1s−1).