Semiconductor crystals that behave exactly as researchers expect are rare, if nonexistent in nature or in lab. Local environment within crystals like defects or surface discontinuities may dominate the properties of semiconductor materials, and often these intractable local impurities limit the performance of clean energy harvest or generation devices like solar cells or LEDs. As part of a collaboration, my project takes a step towards understanding photon generation and loss mechanisms bottom-up by isolating and directly observing single defects within ZnO nanoparticles at atomic level, and correlating their optical properties with theoretical calculations based upon the local environment of single defects. If the observed optical properties of these nanoparticles agree well with calculations predicting the behaviors due to local defects, a framework for studying defect at atomic level can be established to provide significant insight into promising yet less understood material systems.
Adviser: Kai-Mei Fu – Electrical & Computer Engineering