Rapid Preparation of Patterned Conductive Films Based on In Situ Voltaic Cell Templated 3D Controllable Metal Deposition

The fabrication of patterned metal films is essential for a wide range of applications. Here, a novel solution-processing method is presented to achieve the area-selective deposition of copper on aluminum substrates via an in situ Al/CuSO₄/Graphite voltaic cell template. And the copper ions preferentially deposit in the graphite-covered area due to the formed latent image of the potential difference between the graphite-covered area and the blank area on the aluminum surface. Benefiting from the low adhesive force of graphite, the formed copper layer can be easily peeled off and transferred to a flexible substrate to obtain the patterned conductive metal films. By studying the electrochemical properties of different surfaces and the in situ microscopic observation, four stages of electroplating process are proposed. More importantly, a positive correlation between the deposition speed and graphite coverage density is confirmed. This further enables a regional control of deposition thickness in addition to area-selective deposition, which means a 3D controllable metal deposition. Other forms of electroactive carbon are also demonstrated to replace graphite in this method, which offers a versatile and accessible technique to fabricate large-area flexible patterned metal films with defined feature size and controlled resolution from microscale to macroscale.