III–V nanowire backward diodes with high sensitivity above 1 MV W−1 for low-power microwave energy harvesting

Abstract

Improved sensitivity of over 1 MV W−1, which exceeds that of conventional well-designed Schottky barrier diodes, was achieved in p-GaAs0.4Sb0.6/n-InAs nanowire backward diodes (NW BWDs) for low-power microwave energy harvesting at 2.4 GHz under zero-bias. The antimony composition in the GaAsSb NWs was increased to 0.6 to form proper interband tunneling of the BWDs. A linear detected characteristic of detection was obtained even when microwave input power was less than 1 μW. Furthermore, the reduction of parasitic capacitance due to the adoption of a reduced pad area helped in the improvement of the sensitivity of the NW BWDs. A large dynamic range in detection of low-power microwaves was obtained through the employment of an extended anode structure. Device simulations clarified that carrier depletion in GaAsSb NWs was the main cause of increased forward breakdown voltage, which resulted in the large dynamic range exhibited by the NW BWDs.