Harnessing electron correlation to realize UV transparent conductors (Invited Paper)

The combination of a high electrical conductivity while maintaining a high optical transparency is rarely met in conventional materials as it requires to degenerately dope wide band gap semiconductors. The task to find a candidate material with high electrical conductivity and a good optical transparency in the ultraviolet spectrum is an even more daunting task as it requires to realize an ultra-wide band gap semiconductor with a very high carrier concentration. An elegant way out of this dilemma is the utilization of metals exhibiting strong electron correlation. Here, the free carrier absorption edge can be pushed into the infrared regime despite its high carrier concentration due to the carrier mass renormalization arising from a sizeable electron-electron interaction present in these materials, opening up the materials design space of transparent conductor materials towards correlated metals. In this talk I will demonstrate that among possible correlated metal are candidate materials with interband transition beyond 4.5 eV, rendering them suitable as transparent conducting electrodes for deep UV-LED applications.