Background
Thin film deposition of metal oxide materials from aqueous solution is challenged by the solubility and gelling behavior of precursors. For example, some metal cations are poorly soluble at neutral pH, but added acid or base is detrimental to substrate stability and film adherence. In addition, soluble salts of metal cations tend to crystallize rather than gel, leading to poor film morphology without adherence or conformal coverage. An intriguing alternative to water-sensitive alkoxide precursors for spin coating of metal oxide thin films is metal-oxo clusters.
Technology Description
Thin film deposition methods that provide a general process and compositions for solutions of high concentrations of Nb, with or without added alkalis for aqueous thin film deposition of Nb2O5 and ANbO3 (A=any of the alkali metals, or mixed alkali metals). This technology provides methods of making niobate thin film materials with aqueous Nb-concentrations exceeding those of prior methods by up to 4 times.
Features & Benefits
The extremely high solubility and excellent gelation properties lead to smooth coatings and also may be useful to prepare monoliths.
Applications
Solution deposition (spin coating or aerosol spray) of thin films or powders of:
- LiNbO3 for optical materials
- KNN (potassium sodium niobate) ferroelectrics for microelectronics
- Niobate pseudocapacitors
- Electrochromic devices
- Doped or undoped niobium oxide or any alkali niobates for catalysis, memristors, or dielectric materials
Status
U.S. provisional patent application filed