Abstract:The influence of InGaN sub-quantum-well and asymmetric quantum-barrier structures on Al0.2Ga0.8N/GaN Resonant Tunneling Diodes(RTD) are studied based on Silvaco simulator. Theoretical investigation reveals that there are appropriate ranges of the In composition and thickness for InGaN sub-quantum-well which can obviously improve the Negative Differential Resistance(NDR) characteristics of RTD. It is also found that by introducing asymmetric quantum-barrier structures in the sub-quantum-well GaN RTD, the I–U characteristic of Peak-to-Valley Current Ratio(PVCR) can be further improved. Numerical simulation shows that RTD with both InGaN sub-quantum-well and asymmetric quantum-barrier structures exhibits the peak current (Ip) and PVCR of 0.583 A and 5.01 respectively, superior to that of the conventional Al0.2Ga0.8N/GaN RTD without sub-quantum-well having Ip of 0.42 A and PVCR of 1.25. The introducing of improved new quantum structures for the low Al composition AlGaN/GaN RTD has provided one of the solutions to solve the contradiction between the device electrical properties and its actual manufacture for the future terahertz applications.