Enhanced tunneling in the GaAs p~+-n~+ junction by embedding InAs quantum dots

摘要

GaAs p~+-n~+ junctions with and without a layer of InAs quantum dots (QDs) embedded at the interface are discussed in this article. The current density versus voltage (I-V) characteristics show that the junctions without QDs are weak degenerate due to the Beryllium(Be) atoms diffusion of nominal p~(++)-GaAs; the junctions with QDs generate enhanced tunneling current at forward bias, because the QDs layer reduces the Be diffusion and enables a two-step tunneling process. At room temperature, the current density of the sample with QDs is enhanced to 122 A cm~(-2) at a forward bias of +0.32 V, which is about 2 orders of magnitude higher than the reference sample without QDs.