THz sensing of doping concentrations in epitaxial semi-conductors and 2-D electron gases: theory and experiment

This study aims to determine the doping concentrations of an epitaxial doped semiconductor and a 2-D electron gas (GaAs/Al
_0.3
Ga
_0.7
As quantum well) using a reflection based THz imaging system and Hall effect technique. Results show good agreement between the two methods which indicate that the THz measurement is an effective nondestructive means of estimating doping concentrations. The theoretical model however underestimates the doping concentration.