Fabrication of spray-printed organic non-volatile memory devices for low cost electronic applications

• PS:PCBM-based organic non-volatile memory devices was fabricated using spray printing.
• The thickness of the film was controlled by adjusting the concentration of the PS:PCBM solutions.
• The roughness of spray-printed films was poorer than that of the spin-coated film.
• The minimum thickness of the printed film influenced the memory behavior more than the surface roughness.
• The spray printed PS:PCBM showed excellent unipolar switching, reliability, retention, and endurance characteristics.

We fabricated polystyrene (PS) and 6-phenyl-C61 butyric acid methyl ester (PCBM) based organic non-volatile memory devices using a spray printing technique. Due to the distinct operational properties of this technique, significant differences were observed in the macro- and microscopic features (e.g., the film quality and surface roughness) of the devices. The thickness of the film was successfully controlled by adjusting the concentration of the PS:PCBM solutions sprayed. Although the roughness of the spray-printed films was poorer than that of the spin-coated film, negligible differences were observed in the basic memory characteristics (e.g., the operation voltage range, turn on and off voltage, retention and endurance). In particular, the printing-based organic memory devices were successfully switched, as exhibited by the on/off ratio greater than two orders of magnitude at 0.3 V read voltage. The resistance state of all of the devices was maintained for more than 104 s, indicating their non-volatile characteristics.