Weakly bound buffer layers: A versatile template for metallic nano-clusters growth and film patterning on solid surfaces

Buffer layers composed of weakly bound atoms or molecules on solid surfaces are discussed as a versatile platform for size controlled growth of nano-clusters and for patterning of thin metallic films. Metallic nano-crystals can be prepared and their size and density be controlled by varying the film thickness. Cold metallic or oxide clusters, softly land and deposit on solid substrates via the Buffer Layer Assisted Growth (BLAG) method. Their final structure, therefore, reflects purely the interaction with the substrate with no kinetic constraints that may play a role in direct deposition methods of hot atoms. The nature of the buffer film, being a rare gas or a molecular film, can somewhat affect the shape of clusters as well. Applying laser ablation techniques, these weakly bound films were demonstrated to assist in patterning of metallic films. It operates on practically any cold, flat solid substrate that absorbs the laser light. Parallel stripes at sub-micron width, millimeter long, were obtained experimentally, with line width determined by the ablating laser power. The versatility of these weakly bound films in manipulating the structure of metallic particles and thin films is discussed in its wider potential scope.