Electrical Properties and Spectra of Deep Centers in GaN P-I-n Rectifier Structures

GaN p-i-n rectifiers with 4 μm thick i-layers show typical reverse breakdown voltages of 100–600 V. We have studied the temperature dependence of current-voltage characteristics in these diodes, along with hole diffusion lengths and the deep level defects present. Generally we find that i-layer background doping varies significantly (from <10 14 cm −3 to 2–3×10 16 ), which influences the current conduction mechanisms. The hole diffusion lengths were in the range 0.6–0.8 μm, while deep level concentrations were ∼10 16 cm −3 .