Nanostructure tailoring of material properties using controlled crystallization

摘要

The present invention is generally related to controllably modifying or tailoring the structure of crystalline films to adjust and enhance the material properties of the film, such as optical, mechanical and electrical properties. Crystalline films generally refer to microcrystalline (c) film, nanocrystalline (nc) film, polycrystalline (poly-c) film, and other crystallized films. The present invention provides a method for controllably obtaining desired grain sizes (or crystal sizes) in crystalline films and for controllably providing a predominance of grains sizes in a predetermined range to adjust and enhance the optical absorption properties of the crystalline film. The present invention also provide a method for controlling the mechanical properties, e.g., stress formation levels, during crystallization of at least a portion of the precursor film. Through control of the stress formation levels, it is possible to controllably adjust and enhance the electrical properties (e.g., doping efficiencies, carrier mobility, Fermi level and minority carrier lifetimes) of the crystallized portion.