G.D. Watkins - Research Activity

Professor Watkins continues to lead an active research group at Lehigh in the experimental study of defects in semiconductors. The primary techniques presently employed in the group include electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR), which are detected both directly by conventional microwave spectroscopy, and indirectly, by optical absorption and luminescence methods.

Unique to this laboratory is the ability to produce and study simple lattice vacancies and interstitial atoms in a semiconductor crystal by 2.5 MeV electron bombardment in-situ at cryogenic temperatures. This allows the study by EPR of the pristine defects as frozen into the lattice, and then their subsequent migration and interaction with other defects upon warming the crystal. Important impurities are also studied.

The current major effort is on the wide bandgap semiconductors GaN and ZnO.