Carbon dot-dispersed hexabutyloxytriphenylene discotic mesogens: structural, morphological and charge transport behavior†

Abstract

Triphenylene-core grafted 2,3,6,7,10,11-hexabutyloxytriphenylene (HAT4) discotic mesogens were synthesized and their composite matrices have been prepared by dispersing different concentrations of carbon dots (C-dots). The structural, morphological, and charge transport behaviors of the neat and composite matrices have been studied as a function of dopant concentration. The triphenylene matrix remains invariant after the controlled dispersion of quantum sized C-dots; nevertheless, the electronic and transport properties of the neat matrix have been changed significantly. The percolated network of C-dots in the HAT4 matrix offers 102 and 103 times higher conduction current in the columnar and crystalline phases, respectively; however, the charge carrier mobility is found to be reduced due to the surface-recombination and the change in the columnar ordering. In the Colhp phase, the HAT4/C-dots matrix exhibited maximum conductivity and charge mobility of the order of 10−6 S m−1 and 10−2 cm2 V−1 s−1, respectively. The superior behavior of the HAT4/C-dot composites, which could overcome the poor conductivity of organic semiconductors, indicates their potential for practical applications in organic semiconducting devices and optoelectronics.