Abstract
Thin Solid films find ubiquitous applications, but among them, the formation of band-gap engineered superlattices and epitaxial self-assembled nanostructures hold great promise in electronics, opto-electronics and catalysis. The need to tailor-make thin films and nanostructures of desired properties has motivated attempts to understand the initial stages of interface formation, since the morphology of the growing film is the result of a delicate interplay of the thermodynamic and kinetic processes involved. Thus, along with the material properties, growth conditions and quantum effects influence the final outcome of the low dimensional structures and their self-assembly. With the advent of ultra-high vacuum technology and surface sensitive probes, several interesting growth phenomena have been revealed at the atomistic level. I shall present my experimental experience of the formation of model systems in the sub-monolayer regime and in-situ characterization by electron spectroscopic, diffraction and imaging techniques. The deterministic role of lattice mismatch, surface free energy, dangling bonds, etc., in the evolution of the interfaces, will be elucidated. The formation of epitaxial self-assembled nanostructures and surface-phases by employing surface morphologies and reconstructions, as templates, will be demonstrated. The role of Edge Barriers and Quantum Size Effects on growth modes in a metal-semiconductor system, will be discussed. Our attempts to chemically modify ultra-thin films for materials related to GaN band-engineering applications will be demonstrated.
