Laser-Direct Writing of Silver Metal Electrodes on Transparent Flexible Substrates with High-Bonding Strength

We demonstrate a novel approach to rapidly fabricate conductive silver electrodes on transparent flexible substrates with high-bonding strength by laser-direct writing. A new type of silver ink composed of silver nitrate, sodium citrate, and polyvinylpyrrolidone (PVP) was prepared in this work. The role of PVP was elucidated for improving the quality of silver electrodes. Silver nanoparticles and sintered microstructures were simultaneously synthesized and patterned on a substrate using a focused 405 nm continuous wave laser. The writing was completed through the transparent flexible substrate with a programmed 2D scanning sample stage. Silver electrodes fabricated by this approach exhibit a remarkable bonding strength, which can withstand an adhesive tape test at least 50 times. After a 1500 time bending test, the resistance only increased 5.2%. With laser-induced in-situ synthesis, sintering, and simultaneous patterning of silver nanoparticles, this technology is promising for the facile fabrication of conducting electronic devices on flexible substrates.