Simulation of graded-gap ALInN Gunn diodes

We have obtained output characteristics of graded-gap AlInN diodes with different cathode contacts in a wide range of frequencies (fig. 1, table 1). The graded-gap AlInN TEDs can effectively operate in the microwave frequency generation mode up to 0.9 ÷ 1.3 THz. For similar InN-diodes the frequency limit is 0.7 ÷ 0.8 THz. Optimal length of the graded-gap AlInN layer, depending on the active region length and the doping profile is within the range of 0.2 to 0.8 μm. The graded-gap AlInN TEDs exceed InN TEDs of the same type with respect to generation efficiency and output power, but are inferior to them in the optimal generation frequency. Power consumption of AlInN TEDs with high-ohmic heterogeneity at cathode and active region length less than 0.8 μm is by 3 ÷ 20% less than in the InN TEDs of the same type. Within the considered frequency range AlN diodes are inferior to InN and graded gap AlInN TEDs in efficiency, output power and power consumption, as well as in the optimal generation frequency.