Indene‐Based Donor‐Acceptor Type Small Molecular Semiconductors for High‐Performance n‐Channel Transistors

Abstract

AbstractIt is a great challenge to design n‐channel donor‐acceptor (D−A) type small molecules because of the lack of strong electron withdrawing acceptor unit. Herein, 3‐(dicyanomethylidene)‐indan‐1‐one (IC) and 1,3‐bis(dicyanomethylidene)‐indene (IDC) based D−A type small molecular organic semiconductors IC–DDTPTI and IDC‐DDTPTI are synthesized and characterized. Both compounds have low‐lying LUMO energy levels, especially for IDC‐DDTPTI with LUMO energy level lower than −4.0 eV. Thin film transistor characteristics show IC–DDTPTI displays ambipolar transistor behavior with balanced hole and electron mobility. The electron mobility is 0.40 cm2 V−1 s−1 and the hole mobility reaches 0.18 cm2 V−1 s−1. IDC‐DDTPTI exhibits unipolar n‐channel character with an electron mobility of 0.027 cm2 V−1 s−1. These results highlight the applications of IC and IDC units in high performance D−A type n‐channel organic semiconductors.