SYNTHESIS OF NANOSTRUCTURED OXIDE FILMS VIA CHEMICAL SOLUTION DEPOSITION, MOLECULAR DESIGN, AND SELF-ASSEMBLY

摘要

An overview on chemical solution deposition of oxide films is presented in regarding to nanostructure-engineering approaches and their promise in producing nanocrystalline, nanoporous, and mesoporous films or membranes. Results of our deposited films are provided to illustrate the principle that both molecular engineering (via molecular design and self-assembly) and process engineering at either low-temperature synthesis or high-temperature processing conditions are critical to control the final nanoslructure in films (e.g., nanoscale grain or pore size/orientation). Fundamental issues in two general categories of film synthesis, in-situ growth and precursor coating methods, have been discussed. Nanostructure control in films can be achieved by tuning chemical solution chemistry, by controlling nucleation and growth, and by taking advantage of molecular self-assembly on substrate surface or during drying of solutions containing molecular templates. It is shown that in-situ growth in low-temperature solutions could produce desirable nanocrystalline phases in films. Meanwhile, thermal processing as a necessaiy step for the coating approach could also significantly affect the final nanostructure of films.