Electronic materials

The ability to control the movement of electrons is at the core of many technological breakthroughs in the last one hundred years. Computing, energy generation and storage, and the distribution and control of electrical power all build on discoveries of materials with the right electronic properties.

My research interests in this area are motivated by the central role of electronic materials in computing and adjacent areas such as RF technologies.

Impact of growth on the electronic properties of materials

As a natural extension of my interest in growth, a focus of my research has been on the way synthesis and the resulting microstructure condition the electronic properties of the films, particularly at low temperatures, where interactions and kinetics are the difference between a really good material, and a piece of junk.

One of the examples is the growth of ZnO by atomic layer deposition: it can be grown epitaxially at temperatures as low as 100 degrees C, yet the temperature is so low that we can control the distribution of dopants.

I am also interested on the electronic properties of hybrid organic-inorganic materials fabricated via techniques such as sequential infiltration synthesis. This technique allows us to take polymers, including 3D printed materials, and infiltrate them with inorganic materials, resulting on composites with novel optical and mechanical properties.

Similarly, I have explored other systems such as wide bandgap semiconductors. Silicon carbide is a very interesting example, since it can grow on more than one hundred different polytypes, all based on different ways of stacking its atoms. Silicon carbide may not be the hottest material out there, but it is key for advanced power electronics and also provides a pathway to enable computing under extreme environments, such as high temperature and high radiation. It is also a promising subtrate for quantum computing. Finally, SiC is an important constituent of presolar grains, primordial material that predates the formation of the solar system.

Growing high quality SiC is extremely challenging, requiring temperatures exceeding 1500 degrees C. This makes it extremely hard to probe growth using in-situ techniques to understand the mechanistic aspects involved in the formation of these materials. Over the past years, I have been involved in a number of projects involving the development of models to try to capture the evolution of microstructure during SiC growth and, from an experimental point of view, develop developing new ways of accessing these growth conditions using synchrotron radiation. I am also part of a project looking into the device degradation under neutron bombardment.

Recently I have also explored the microstructure and electronic properties of gallium oxide: gallium oxide is a novel wide bandgap semiconductor with a monoclinic crystalline structure and the potential to yield large single crystal substrates, something that it is much harder to achieve in other comparable materials such as silicon carbide or gallium nitride. Therefore, it is an interesting material to keep an eye on, and it is the focus of one of my current research projects.

Design principles for electronic materiasl for brain-inspired computing

Another area or current interest is on beyond CMOS approaches and in particular on neuromorphic computing. One of the fascinating aspects for me on this area is the strong coupling between materials, architectures, and computing, and the need of developing new materials with new functionalities.