Selective Photonic Patterning of Molecular Ink

Example 5

The molecular ink I3 was deposited as a 2 cm circular trace on a PET substrate. A triangular opening was cut out of a first card and the triangle cut out was centered over the 2 cm circular trace. Slots were cut out of a second card and the slots were centered over a second 2 cm circular trace. The covered traces were then exposed to a DYMAX 5000-EC Series UV Curing Flood Lamp system at a distance of 10 cm from the bulb for about 200 s. Over the duration of the exposure, the temperatures of the exposed part (E) and covered part (C) of the trace were measured, with the results shown in FIG. 5A. As seen in FIG. 5A, the temperature of the exposed parts (E) reached about 150° C. after 120 s, whereas the temperature of the covered parts (C) reached only about 70° C. after 120 s and reached no higher than about 90° C. during the sintering process. After exposure, the trace was washed with methanol, which readily removed the unreacted covered parts of the trace, while the exposed parts remained bound to the PET substrate. FIG. 5B illustrates the pattern formed from the triangular opening and FIG. 5C illustrates the pattern formed from the slots.