Teilprojekt 9
TP 9
Deposition and characterization of epitaxial LiNbxTa1-xO3 films
This subproject deals with the epitaxial deposition of LiNbxTa1-xO3 thin films with pulsed laser deposition (PLD) on oxide substrates. Compared to the corresponding bulk materials (3D), the properties of thin films can differ significantly due to the reduced dimensionality (2D). In addition, interfaces and surfaces play a much more prominent role than with bulk materials. The introduction of mechanical strain through heteroepitaxial deposition also offers new degrees of freedom to specifically modify the physical properties of the layers (strain engineering). The overall aim of this subproject is therefore the fundamental investigation of the growth process of epitaxial LiNbxTa1-xO3 thin films over the entire composition range from x = 0 to x = 1 using PLD as well as the influence of the growth parameters on the structural, physical and chemical film properties. For this purpose, the growth conditions (temperature, oxygen partial pressure, target composition, target-substrate distance, laser fluence/frequency) must be optimized with regard to a stoichiometric composition of the layers without foreign phases and high structural quality without rotational domains. The use of lattice mismatched oxide substrates allows the growth of heteroepitaxia
Objektives
- Deposition of stoichiometric, epitaxial LiNbxTa1-xO3 layers (with x between 0 and 1) with low defect density
- Optimization of PLD parameters using a machine learning approach
- Influence of composition, lattice strain and layer thickness on structural, chemical and physical layer properties heteroepitaxia
