Small-area deposition of light emission polymer by evaporative spray deposition from ultradilute solution technique

The evaporative spray deposition from ultradilute solution (ESDUS) technique has enabled the preparation of organic, devices from highly diluted solutions of polymer semiconductors. Here, we report another feature of this technique, the pixel-size deposition of a pi-conjugated polymer. Small-area coating was carried out using a simple shadow mask with pixel-size holes. A blue-emission polymer, PFHB, was deposited through the mask. The resultant film had a pixel pattern of 10 mu m separation. Moreover, a green-emission polymer, CN-PDHFV, was subsequently deposited over the first patterned layer. The pixel pattern was maintained clear without getting blurred even using the same solvent, tetrahydrofuran, for each polymer deposition. An electroluminescent (EL) device consisting of a patterned partial double layer showed a green emission from a single layer area.