Selective electrodesorption-based atomic layer deposition (SEBALD) of bismuth under morphological control

The development of next-generation electronics is very dependent on the discovery of materials with exceptional surface-state spin and valley properties. Bismuth has most of the characteristics required for technological development in this field. Thin films of this element have shown nontrivial topology enabling their definition as a topological insulator and a distribution of spin states and valleys in the band diagram that are suitable for both spintronics and valleytronics applications. In some cases, these properties depend on the quantum confinement of the related particles or quasi-particles; hence they can be tuned by varying the thickness in the ultrathin film range. Finally, thin films of Bi can be processed by electrochemical lithographic methods. Bismuth ultrathin films can be obtained by techniques that require vapor phase with different degrees of vacuum (e.g., PVD and CVD). These methods are efficient for producing flat polycrystalline thin films of Bi. Similarly, Bi thin films were electrodeposited from an aqueous solution containing organic additives with multiple morphologies and textures according to the different surface effect promoted by these substances. These studies have demonstrated that Bi thin films are among the wide range of technologically interesting coatings that cannot be easily obtained from aqueous solutions without interference from metal oxide growth. In most cases, these processes lead to films with uncontrolled morphology.