Integrated Calendar

I will give examples from various fields to show the ubiquity of oxides for a number of applications. Compared to dominantly covalent semiconductors like silicon and the III-V or II-VI materials oxides are primarily ionic bonded and also have extensive oxygen bonding and the oxygen bonds play a crucial role in determining the property of the material and give oxides a level of diversity not seen in covalent semiconductors.
It is frequently argued by the semiconductor community that oxides are prone to defects and hence are inherently unstable for technologies. However, defects in oxides play a crucial role in controlling the material properties and I will illustrate this with the example of ferromagnetism in TiO2 via titanium vacancies. This is achieved by substituting Ta in the place of Ti which leads to a significant donor electron population stimulating the formation of compensating defects such as Ti vacancies and Ti3+. As a function of film thickness one sees ferromagnetism, Kondo scattering and eventually impurity scattering in the same system revealing the diversity of interactions.
For the technologies beyond Moore silicon photonics is evolving at a rapid phase with a corresponding Moore’s law projection extending up to 2025. The area of opportunity is the growth of functional oxides on silicon to build switchable devices which will significantly enhance the capability of the future silicon packages integrating multiple chips.
In today’s computing devices more than 25% of the energy is consumed in memories and a typical server station expends 55% of its energy on memories. Ferroelectric tunnel junctions may play a crucial role in the development of low energy consuming memory devices. I will show results on oxide based ferroelectric tunnel junctions where just two unit cells of barium titanate enable a robust switching of a junction with On/Off ratios exceeding 1000%.
Oxides, because of their chemical stability may be important for applications such as water splitting, CO2 sequestration etc. I will illustrate this with the example of a new class of materials, Sr, Ca and Ba Niobates which show a very unusual band structure when prepared under different oxygen pressures.
Lastly but not the least I will illustrate the potential for oxides in controlling bio processes such as bio film formation cell proliferation and differentiation where the surface chemistry seems to play a crucial role in controlling the processes.