writer：Haoran Xu, Jin Feng, Chengchao Xiao, Rui Xu, Yi Xie, Tao Zhou*
keywords：laser activator, laser activation, NIR, UV, metallization, Au-Ni-Cu layer
source：期刊
specific source：ACS Applied Materials & Interfaces, 2022, 14, 31411-31423
Issue time：2022年
In laser-induced selective metallization (LISM), conventional laser activators only worked under a single laser wavelength. This study reported a new laser activator (MoO3) very suitable for both 355 nm UV and 1064 nm NIR lasers for the first time. When applying MoO3 to polymers, the prepared Cu layer on laser-activated polymers showed good conductivity (2.63×106 Ω-1·m-1) and excellent adhesion. SEM, optical microscope and resistances revealed the excellent LISM performance of the polymer/MoO3 composites, and the quality of the prepared Cu layer from UV laser is much better than NIR laser. The limit width of the copper wire prepared by UV laser reached as narrow as 30.1 μm. We also confirmed the mechanism of MoO3 initiating ECP after laser activation was the autocatalytic mechanism, which is very different from the conventional reduction mechanism. The effect of laser activation was only to expose the MoO3 active species to the polymer surface. XRD and tube experiments revealed that the activity of α·h-MoO3 was higher than α-MoO3. XPS indicated a part of Mo6+ was reduced to Mo5+ during laser activations, leading to the increase of the oxygen vacancies in MoO3 and possibly further enhancing the activity of MoO3. Besides, the micro-rough structures caused by laser on the polymer surface provided riveting points for successfully depositing the copper layer. The Ni-Cu, Ag-Cu, and Au-Ni-Cu layers were obtained via the continued to deposit of other metals on the Cu layer. The resistances of these metal layers had much better stability than the neat Cu layer. Furthermore, the Au layer further enhanced the conductivity of the circuit. The proposed strategy is easy for large-scale industrial applications, which will greatly expand the application scenarios of the LISM field.