Coordinatable and High Charge-Carrier-Mobility Water-Soluble Conjugated Copolymers for Effective Aqueous-Processed Polymer-Nanocrystal Hybrid Solar Cells and OFET Applications

A water-soluble conjugated polymer (WCP) poly[(3,4-dibromo-2,5-thienylene vinylene)-co-(p-phenylene-vinylene)] (PBTPV), containing thiophene rings with high charge-carrier mobility and benzene rings with excellent solubility is designed and prepared through Wessling polymerization. The PBTPV precursor can be easily processed by employing water or alcohols as the solvents, which are clean, environmentally friendly, and non-toxic compared with the highly toxic organic solvents such as chloroform and chlorobenzene. As a novel photoelectric material, PBTPV presents excellent hole-transport properties with a carrier mobility of 5 x 10(-4) cm(2) V-1 s(-1) measured in an organic field-effect transistor device. By integrating PBTPV with aqueous CdTe nanocrystals (NCs) to produce the active layer of water-processed hybrid solar cells, the devices exhibit effective power conversion efficiency up to 3.3%. Moreover, the PBTPV can form strong coordination interactions with the CdTe NCs through the S atoms on the thiophene rings, and effective coordination with other nanoparticles can be reasonably expected.