Liquid Metal Transport Crystal Growth: A Liquid Phase Deposition Strategy for On-Substrate Design of Metal Crystals.

Liquid phase deposition is widely employed for growing substrate-supported thin films and structures. While this strategy usually shows fast growth kinetics compared with vapor phase deposition, it imposes less control over crystalline phases, morphologies and orientations at the individual crystal level. Here we demonstrate a metallic liquid phase deposition method for growing substrate-supported, highly faceted metal crystals with diverse phases and morphologies. During the liquid metal transport crystal synthesis, a metallic solvent dissolves a chosen solute metal and carries the solvated zero-valence atoms to a target substrate, where it deposits as microscopic crystals. The use of low-melting-point gallium as the transport solvent allows crystal phase, facet, size and shape to be regulated at low temperatures and a range of monometallic and bimetallic crystals to grow on various substrates. We perform Wulff construction and ab initio molecular dynamics simulation to explain the energetics and growth habits that lead to the observed morphological diversity. This work expands the widely liquid phase deposition method to metallic solvents for fine-tuning the composition, morphology and crystalline properties of substrate-supported metal crystals.