Charge transport in phenazine-fused triphenylene discotic mesogens doped with CdS nanowires

Abstract

Herein, we report the synthesis of oleylamine-capped CdS nanowires (NWs) and the dispersion of a small optimized amount of these NWs in the Col_h phase of a recently synthesized phenazine-fused-triphenylene discotic liquid crystal (PFT DLC) to understand the temperature-dependent charge transport via the time-of-flight technique. X-ray diffraction study reveals a reduction in core–core separation; however, upon doping CdS NWs, we observed a trivial decrease in hole mobility. For the PFT-DLC and its composite, the hole mobility was found to be in the range of 0.07–0.43 × 10⁻³ cm² V⁻¹ s⁻¹ following the inverse-power law as a function of temperature. This could be due to the large size of the CdS NWs, which eventually disturb the Col_h packing and hence the charge carrier mobility. Besides, a nanocomposite device consisting of the heterojunction of ITO–PFTDLC/CdS–Au has been constructed and I–V characteristics were obtained, which obey Ohm's law under a limiting case of the Poole–Frenkel conduction mechanism.