A new lattice-matched In 0.17 Al 0.83 N ∼ GaN based heterostructure IMPATT diode for terahertz application

Simulation studies are made on the dc and microwave performance of a novel lattice-matched In 0.17 Al 0.83 N/GaN heterostructure impact avalanche transit time (IMPATT) diode designed at the low-end terahertz frequency of 220 GHz. The electric field, breakdown voltage, rf output power and the dc-to-rf conversion efficiency of the heterostructure IMPATT diodes are compared with the GaN homostructure IMPATT diode. The results show that, a more localized avalanche region width is obtained for the heterostructure IMPATT diodes. With value of 45 nm of the In 0.17 Al 0.83 N layer width, the heterostructure IMPATT diode gives the highest efficiency (15.4%) with moderate rf output power density (1.62 MW cm −2 ), and the lowest Q -factor (6.57) as compared to other heterostructure and homostructure IMPATT diodes.