Figure 2

Optical micrographs of BPEA single crystal arrays fabricated on the different substrates.
(a) Large-area arrays of single crystal ribbons with the length approaching millimeter scale on the SiO2 substrate. (b) The enlarged image of highly-ordered single crystal arrays on the SiO2 substrate, where every individual ribbon has a uniform color and a straight line in the shape. (c) Well-aligned organic ribbons achieved on (c) PI substrate and (d) Glass substrate. These images suggest that the formation of single crystal ribbons is independent of the substrate.