Modification of an extrusion-based 3D printing technology for thin-film printing for electronic device applications

High-resolution 3D printing technologies can print thin films; however, they are not commonly available because of their high initial cost, and the majority of them employ a pneumatic-driven printing technique that hinders retraction, which is crucial for printing complex geometries. The main objective of this paper is to modify an extrusion-based 3D printing technology and investigate its potential for thin-film printing for electronic device applications like perovskite solar cells (PSCs). The modification is done by replacing the filament extrusion system with a liquid extrusion system using a syringe pump. CAD software, CATIA V5R20, is used to model the parts of the syringe pump, which are then 3D printed from polylactic acid (PLA) filaments. To validate the functionality of the modified 3D printer for thin-film printing, a physical experiment is conducted to print a poly 3,4-ethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS) solution, a widely used conductive polymer, by varying the 3D printing parameters, namely; print speed, bed temperature, nozzle diameter, and x-distance offset. Based on the experiment, a thin PEDOT:PSS film was successfully printed with a thickness of 142 nm and a notable level of surface uniformity when compared to the spin coating. Further, the modified 3D printer is utilized to print a PEDOT:PSS and a perovskite methylammonium leadtriiodide-chloride (CH₃NH₃PbI_3 − xCl_x) solution in a layer-by-layer fashion sequentially and tested for validity for perovskite solar cell (PSC) application by printing other layers of PSC on top of the perovskite layer using the spin coating method. Based on the test conducted, a competitive open-circuit voltage of 740 mV was successfully generated from the printed PSC. Finally, it has been observed that extrusion-based 3D printing technology can be modified and optimized to print thin films for PSC applications. This has tremendous advantages for rapidly printing and testing electronic devices in general, and PSCs in particular.