Luminescence, charge mobility, and optical waveguiding of two-dimensional organic rubrene nanosheets: Comparison with one-dimensional nanorods

Intrinsic characteristics of organic and inorganic nanostructures depend on their physical dimensions (i.e., size and shape) and crystallinity. Here, we compared the nanoscale optical and electrical properties of organic rubrene one-dimensional (1-D) nanorods (NRs) and two-dimensional (2-D) nanosheets (NSs). From high-resolution laser confocal microscope photoluminescence (PL) measurements, the light-emission characteristics of 2-D rubrene NSs varied with the crystalline domain direction, indicating intrinsic PL anisotropy, which was distinguishable from 1-D rubrene single NRs, because of anisotropy π–π stacking molecular arrangements. We also observed the variation of charge carrier mobility depending on the measured directions (i.e., anisotropy of charge transport) in rubrene NS-based field-effect transistors. The optical waveguiding properties of rubrene nanostructures were strongly correlated to the dimensionality of materials and PL anisotropy.

The light-emission characteristics of a two-dimensional rubrene single nanosheet (NS) varied with the crystalline domains, which were correlated to the anisotropy of charge mobility and optical waveguiding.Figure optionsDownload as PowerPoint slideHighlights
► Nanoscale photoluminescence and change transport characteristics of 1-D and 2-D rubrene nanostructures.
► Anisotropic luminescence of 2-D NS correlated to charge mobility and optical waveguiding effects.
► Crystalline domains and anisotropic π–π stacking determine characteristics of rubrene nanostructures.