Printing Parameters Optimization of Inkjet Printed Solar Electrodes with Controllable Aspect Ratios

Solar electrodes with controllable aspect ratios are realized by inkjet printing technology with optimized parameters. Droplet spacing is an important parameter to control the width of the deposited line. Electrodes with a minimum line width below $50\mu \mathrm{m}$ are achieved when the droplet spacing is $38\mu \mathrm{m}$. Three-dimensional morphologies of electrodes are mainly affected by the substrate temperature and the number of printing passes. Different cross-sectional morphologies can be obtained by changing these two parameters. It is found that 80 ∼ 90°C is the optimum temperature range for forming high aspect ratio morphology and the line height can be controlled by the number of repeat printing passes. Temperature related coffee ring effect leads to nonuniform morphologies of electrodes and the causes of coffee ring defects are studied.