Indium-based interface systems, structures, and methods for forming the same are provided. The disclosed indium-based interfaces may be formed as solid structures between two solid surfaces by providing a solid indium-based material between the two surfaces, and heating the indium-based material above its melting point while in contact with each of the two surfaces to cause the indium-based material to reflow or otherwise liquefy between the two surfaces. The indium-based material may then be cooled below its melting point to form a solid interface material structure that is positioned between and in contact with each of the surfaces.