Effect of molecular architecture on morphology in the nanostructures and its applications in superhydrophobicity and organic photovoltaics

Abstract

Morphological structures with respect to the effect of carbazole derivatization, which are based on conjugated donor–acceptor moieties, are presently explored. In this work, light management studies, organic photovoltaics devices and surface properties are systematically investigated. Two carbazole derivatives Cz–Bt (carbazole–benzothiadiazole) and Cz–Bt–BT (carbazole–benzothiadiazole–bithiophene) are electrosprayed, resulting in triangle and spike (2-D and 3-D pyramids) structures, respectively. These 2-D and 3-D pyramids differ due to an additional bithiophene unit at the molecular level, which has imparted a higher degree of rotational freedom. The effects of derivatives, solution concentrations and solvents vapor pressure on morphology are studied. Further, these submicron-size pyramids are characterized by enhancement in light absorption due to scattering and multi-reflection. It is observed that 2-D pyramids enhance up to 44.4%, whereas 3-D pyramids enhance up to 18.7% of light absorption. Subsequently, these structures are characterized in organic photovoltaics architecture, using various layer design strategies, and, thus, we able to obtain insights about layer addition, with respect to structures size and morphology. In addition, the effect of fabrication procedure assisting in an increase in hydrophobicity is also demonstrated.