vaporsolid

Vaporsolid refers to a class of deposition processes in which material is transferred from the vapor phase and directly incorporated into a solid on a substrate, without an intervening liquid phase. It is commonly described in contrast to vapor-liquid-solid (VLS) mechanisms that rely on a liquid catalyst. In vapor-solid (VS) growth, crystal formation occurs via direct adsorption of vapor species, surface diffusion, and incorporation at energetically favorable sites such as step edges or defects.

Growth can take place in chemical vapor deposition (CVD) or physical vapor deposition (PVD) environments. Depending on chemistry, VS processes may involve gas-phase reactions that yield a solid film on the substrate, or direct condensation of atomic or molecular species. Growth conditions such as substrate temperature, pressure, vapor flux, and precursor reactivity control thickness, crystallinity, and morphology.

Materials commonly grown by VS methods include semiconductor oxides (ZnO, TiO2, SnO2), gallium nitride (GaN) and other III-nitrides, silicon carbide, and various metallic or nitride films. VS is especially valued when avoiding liquid catalysts preserves material purity or when liquid catalysts would be impractical due to reactivity or contamination concerns.

Advantages of the vapor-solid approach include simplicity, reduced risk of catalyst contamination, and compatibility with high-temperature processing. Limitations encompass control over nanostructure morphology, crystal quality at low temperatures, and relatively slower growth rates in some systems.

History: The concept aligns with established CVD and PVD practices, with the VS designation emphasizing direct vapor-to-solid mass transport and growth.