A novel multifunctional C3-symmetric triphenylamine discotic liquid crystal: synthesis, columnar self-assembly, organogel behavior, selective detection of PA and application in Si solar cells

Herein, a novel multifunctional C3-symmetric triphenylamine discotic liquid crystal TPAP12 was successfully synthesized via Suzuki coupling reaction as the key step and fully characterized by NMR, HRMS, and TGA. The liquid-crystalline and gel properties of TPAP12 were investigated using POM, DSC, XRD, electron density maps, and SEM. TPAP12 can self-assemble into a hexagonal columnar phase liquid crystal in the pure state and form organogels in 1,4-dioxane and n-butanol, respectively. Additionally, TPAP12 can be employed as a fluorescent probe to rapidly (within 5 s) detect picric acid (PA) with a determination limit of 3.06 nM. Furthermore, TPAP12 as a dopant was introduced into the PEDOT:PSS hole injection layer, leading to a significant improvement of the power conversion efficiency of Si/PEDOT:PSS heterojunction solar cells from 10.46% to 12.5%. The present study provides a new approach to designing multifunctional triphenylamine liquid-crystalline materials.