Skip to main content

Todd Karin

We need viable green technologies to reduce global carbon emissions, but the physical materials that make up these technologies are not fully understood. The III-V semiconductor material system takes a prominent place in the arsenal of light-harvesting and light-producing technologies: it is used in commercial LEDs and in the highest efficiency solar cells. While III-V materials are well studied, there are still questions surrounding the optical and electronic properties of common crystal defects.

In semiconductor devices, defects play a central role in determining device operation and efficiency. Even small number of defects can dominate semiconductor properties. For example, solar cells are made by incorporating impurity atoms at a concentration of one in a million host atoms. Unwanted defects on the other hand, even at low concentrations, can interfere with device function.

I develop new tools to study crystal defects in the pure III-V material system, with the goal of applying these techniques to study novel or dirtier materials. A fuller understanding of defects in III-V materials will be crucial for designing next-generation green technologies.

Advisor: Kai-Mei Fu, Physics