Trap-dependent current suppression of optically excited III-V nanowires at cryogenic temperatures
The advancement of quantum technology networks necessitates high-speed, low-thermal load, and minimal-noise communication links between cryogenic and room-temperature components. At the heart of modern telecommunication, lay optical interconnects allowing for large data transfer capabilities via optical fibers. However, cryogenic photonic technologies remain largely unexplored and require a detailed understanding of material behavior and defect dynamics at low temperatures. In this work, we present the first comprehensive study of integrated III-V heterostructures operating at cryogenic temperatures down to 5K. Using an integrated n-InP/i-InGaAs/p-InP/p-InGaAs stack monolithically grown on silicon, we identify a temperature-dependent current-lowering mechanism arising from trap states becoming increasingly active below 140K. We demonstrate for the first time that these traps can be equivalently excited and controlled through either thermal or optical energy, revealing a dual modulation mechanism. These findings provide new insights into carrier transport and defect behavior in III-V heterostructures at cryogenic temperatures, advancing the field of cryogenic photonics and offering a non-destructive approach for identifying and characterizing material impurities in integrated quantum and optoelectronic devices.