SFB Colloquium

Transition metals oxides offer scientists and engineers a wide spectrum of exciting physics, with complex structure-property relations and a range of useful phenomena. Advances in epitaxial techniques have unlocked unprecedented possibilities of atomic engineering of these oxides and their interfaces, with exciting prospects of unravelling their underlying physics and harnessing it towards useful applications.

One promising approach towards driving these materials towards applications is integrating functional oxides with conventional semiconductors. I will present some of the challenges and technical approaches for implementing this concept, and address the electronic transport across the oxide-semiconductor interface. We implemented such structures in solar-to-chemical energy conversion scenario, by photoelectrocatalytic water splitting. The benefits, hurdles and improvement potential of this approach will be discussed.

The second part of the talk will be dedicated to oxide 2D electron gases (2DEGs) and their integration with semiconductors. While challenging, this approach can be considered as the first step toward bridging between oxide electronics and silicon technology. The growth and transport properties of titanate heterostructures will be presented, exhibiting the formation of oxide 2DEGs directly on semiconductors. Challenges in the growth of these structures result in structural imperfections; analysis of the 2DEG transport behavior in comparison to more standard growth schemes provides insight into the role of defects and oxygen vacancies. Can these observations be extended to general cases of oxide 2DEGs?

These examples of ‘vertical’ (out of plane) and ‘lateral’ (in plane) electronic transport will be discussed as potential device building blocks. With these, I hope to convey some of the excitement, promises and challenges of coupling oxides with semiconductors.