Growth condition effects on the structure evolution and electrical properties of low-melting-point bismuth films

Abstract

Bismuth (Bi) is a low-melting-point semimetal material with unique physical properties, and it has great potential for use in spintronics devices and contact electrodes based on two-dimensional materials. Based on the growth conditions, an expanded structural zone model (SZM) is proposed for this type of polycrystalline low-melting-point semimetal film. The growth mechanism and morphology evolution of Bi film are further analyzed based on the deposition temperature, growth rate, and film thickness. At a high substrate temperature, the Bi film grows with a preferential orientation, and the boundary temperature of zone II becomes larger. Meanwhile, the thickness has a relatively significant effect on the SZM of low-melting-point Bi film. The film growth mode of the zone II interval results in the competitive growth of texture. Furthermore, the growth rate has a significant effect on the in-plane grain size and the surface roughness of the low-melting-point Bi film. This study provides important insights into the controlled growth and transport characteristics of low-melting-point Bi film.