Coaxial Conjugated Polymer/Quantum Rod Nanowires with Preferred Quantum Rod Orientation

One-dimensional crystalline fibrillar assemblies of poly(3-hexylthiophene) (P3HT)-based materials

hold significant potential for fabrication of low-cost optoelectronic devices. Here we show the kinetically controlled crystallization-driven assembly of poly(3-hexylthiophene)-b-poly(2-

vinylpyridine) (P3HT-b-P2VP) conjugated polymers (CPs) and quantum rods (QRs) to generate p-n coaxial hybrid nanowires (NWs) with the desired QR alignment mode (end-to-end or side-by-side coupling) in a 1D nanolane. Co-crystallization of CPs and QRs, through the diffusion of a poor solvent to a good solvent containing the two components, allows NW formation through the structural evolution of CP-bridged QR dimeric seeds. The coupling mode of the QR array within a single NW is determined by the balance between the van der Waals and dipole-dipole interactions between QRs during the CP assembly. Because the interparticle attractive forces that provide a real colloidal system favor the misalignment of colloids, it is normally difficult to achieve the desired order of QRs. However, the location and orientation of QRs confined by CP bridging can be controlled kinetically by varying the solvent mixing rate affecting the CP crystallites and growth. This is confirmed by 3D electron tomography. This work provides a deep understanding of the complex and competitive

assembly of polymers and nanoparticles to form sophisticated nanohybrids. Moreover, it paves the way to overcoming the poor ability of nanorods to form a large area of oriented arrays, which is important in both fundamental research and applications, especially the performance optimization of

optoelectronics, photonics, and sensors.