Dipole-assisted self-assembly of light-emitting p-nP needles on mica

Abstract

We report on dipole-assisted, self-assembled formation of p -6P and p -5P needles on cleaved and heated mica (0001) surfaces. Low-energy electron diffraction (LEED) reveals that the needles are single crystalline with the (11̄1̄) face parallel to the surface, consisting of parallel stacks of laying molecules oriented along the direction of microscopic dipoles on the mica surface. They have submicrometer cross-sectional dimensions and lengths as large as millimeters. Moreover, due to the strong dipole confinement of individual molecules, the needles form large domains with parallel oriented entities. A pronounced optical dichroism agrees with the findings from LEED.