Nanowire Crystals of a Rigid Rod Conjugated Polymer

Xiong Gong, The University of Akron

Abstract

In this paper, we show that well-defined, highly crystalline nanowires of a rigid rod conjugated polymer, a poly(para-phenylene ethynylene)s derivative with thioacetate end groups (TA-PPE), can be obtained by self-assembling from a dilute solution. Structural analyses demonstrate the nanowires with an orthorhombic crystal unit cell wherein the lattice parameters are a ≈ 13.63 Å, b ≈ 7.62 Å, and c ≈ 5.12 Å; in the nanowires the backbones of TA-PPE chains are parallel to the nanowire long axis with their side chains standing on the substrate. The transport properties of the nanowires examined by organic field-effect transistors (OFETs) suggest the highest charge carrier mobility approaches 0.1 cm2/(V s) with an average value at 10−2 cm2/(V s), which is 3−4 orders higher than that of thin film transistors made by the same polymer, indicating the high performance of the one-dimensional polymer nanowire crystals. These results are particular intriguing and valuable for both examining the intrinsic properties of PPEs polymer semiconductors and advancing their potential applications in electronic devices.