Point defect determination by photoluminescence and capacitance-voltage characterization in a GaN terahertz Gunn diode

Photoluminescence (PL) measurement is used to study the point defect distribution in a GaN terahertz Gunn diode, which is able to the degrade high-field transport characteristic during further device operation. PL, secondary ion mass spectroscopy (SIMS), transmission electron microscope (TEM), and capacitance-voltage (C-V) measurements are used to discuss the origin of point defects responsible for the yellow luminescence in structures. The point defect densities of about 10¹¹ cm^-2 in structures are extracted by analysis of C-V characterization. After thermal annealing treatment, diminishments of point defect densities in structures are efficiently demonstrated by PL and C-V results.