Electrical behavior of laser-sintered Cu based metal-organic decomposition ink in air environment and application as current collectors in supercapacitor

Abstract

Cu based metal-organic decomposition (MOD) ink has been preferred as a printable conductive material in the field of printed electronics because it can mitigate the formation of undesired Cu oxide or precipitation of the metal source during storage and printing. However there will be oxidation of Cu during sintering process in air environment, for fabrication of conductive track from printed ink. In this paper, possibility of laser-sintering of Cu MOD ink in air was studied. The Cu MOD ink was spin-coated on polyimide (PI) substrate. The laser with 355 nm wavelength was accommodated as a heat source in this study. The parametric study with various laser power intensities and scan rates, showed 230-557 W/cm2 and 1-8 mm/s as the feasible laser-sintering process window. As a result, the specific resistance of the laser-sintered Cu MOD ink was achieved 21 μΩcm which was about 10 times as much as that of bulk Cu. As an application, laser-sintered Cu MOD ink was confirmed to give acceptable performances compared to traditional Cu sheet electrodes as flexible current collectors of the supercapacitor.