Effects of 3D printer parameters on conductivity of Nano-titanium dioxide on electrode solar cells

Abstract

Fabricating conductive materials on electrode of electronic devices with printing techniques continues to gain popularity, including 3D printing especially Liquid Deposition Modelling (LDM) technology which is being interested in electronics industry. This research applied LDM 3D printing to fabricate nano-Titanium dioxide (TiO₂) thin film on an electrode or anode. The aim of research was to study the effect of parameters for setting the printer, such as nozzle size, printing speed, air pressure and nozzle distance from the electrode surface, on the quality of TiO₂ thin film and related sheet resistance. The experiment began with the paste samples preparation by mixing between the ready-made nano-TiO₂ PST-18NR (P25) with ethanol 99.5% and the flow of each paste was considered. Then a printing test was performed by adjusting the combination of the variation of the printer parameters. The obtained wet thin films were annealed in a chamber at temperature of 500 degree Celsius for 4 hours. The dried thin films’ characteristics were analyzed by evaluating uniformity, thickness, roughness, cracking and sheet resistance which led to achieve good quality electrode. The results showed that the rheology of TiO₂ paste sample was important to set the printer parameters to give the proper force to extrude the TiO₂ paste with optimum thin film thickness without crack. The obtained sheet resistance of thin films was between 5.10 – 5.77 MΩ/Sq which was able to construct the DSSCs. This printing condition had limitation on the thin film thickness at only 6 ±0.25 µm and multiple printing had no effect on the increase of thin film thickness significantly. The conversion efficiency of DSSCs was 4%. Interestingly, this study confirmed the possibility of designing the thin film with various shapes, by which the efficiency conversion of solar energy showed at averaged 3%.