Carbon Nanotube-Conducting Polymer Core−Shell Hybrid Using an Imidazolium-Salt-Based Ionic Liquid As a Linker: Designed As a Potential Platinum Electrode Alternative Material for Large-Scale Solution Processing

A core−shell carbon nanotube/conducting polymer hybrid, using an imidazolium-salt-based ionic liquid as a linker, has been developed for large-scale solution processing of CNTs. Dye-sensitized solar cells (DSCs) with the solution processed hybrid film as the counter electrode exhibit comparable photovoltaic performance to that of devices with the conventional Pt counter electrode. A strategy developed is extremely simple and effective with good environmentally compliance. The water-soluble shell (1) promotes dispersion of the CNT aggregates and brings individual CNTs into aqueous solution while maintaining intact π-conjugation structure and (2) leads to a reduced charge injection barrier and realizes high photovoltaic performance. This work paves a way for high-performance optoelectronic and solar energy conversion devices of large-scale applications.