Optimum current-voltage characteristics of GaAs/AlAs intraband microwave devices

In this reported work, both high peak current density and high peak-to-valley current ratio (PVCR) in AlAs/GaAs triple-barrier quantum-well intraband resonant tunnelling diodes (TBQW IRTDs) were accomplished. The valley current density (J(V)) of TBQW IRTDs can be degraded as the barrier thickness reaches 4 nm thickness. This result suggests narrow barrier thickness is due to the slight band bending effect in the conduction band of i-AlAs barrier layers. The peak current density (J(P)) of the TBQW IRTDs will be <2.43 KA/cm(2) as the i-AlAs barriers thickness of the TBQW IRTD reaches 5 nm thickness. The optimal thickness of barrier layers should be selected at 4 nm thickness to obtain the highest PVCR value (about 4270), in which the sample with barrier layers of 4 nm thickness possesses the lowest valley current density.