Low Temperature Deposition of Vanadium Dioxide on III–V Semiconductors and Integration on Mid-Infrared Quantum Cascade Lasers

We demonstrate low temperature deposition conditions for vanadium dioxide (VO2) phase change material by pulsed laser deposition, which are compatible with III–V semiconductors heterostructures typically used in optoelectronic applications. The characterizations of the VO2 coated thin films grown on GaAs show a 50% change in optical reflectivity in the mid-infrared range and a variation of electric conductivity of two orders of magnitude between the insulating (low temperature) and the metallic (high temperature) states. The transition temperature is estimated around 68 °C (341 K). We also study the functionalization of mid-infrared quantum cascade lasers (QCLs) (operating at wavelengths λ ∼ 7–8 μm) with VO2 layers, in view of engineering the laser emission properties with an integrated VO2 layer. We demonstrate QCLs that integrate a VO2 layer on the surface that interacts with the guided laser mode. A maximum operating temperature of 61 °C (334 K) has been measured.