Integration of vertically-aligned carbon nanotubes with superconducting nanowire single photon detectors

Abstract

Abstract We report on initial fabrication efforts in the integration of superconducting nanowire single-photon detectors (SNSPDs) with vertically aligned carbon nanotubes (VACNTs) with the goal of creating a wideband single-photon detector. SNSPDs provide high detection efficiencies and low dark count rates, while the VACNTs are excellent broadband optical absorbers. Combining these technologies could potentially enable the development of highly sensitive and versatile optical sensors for a variety of applications, such as spectroscopy, optical communication, and imaging in light starved environments. We developed two fabrication processes for the integration of VACNTs on SNSPDs. The first involves capping the SNSPDs with a protective layer and growing the VACNTs directly above nanowires. Thermal and electrical characterizations of the devices demonstrated a degradation of the superconducting qualities of the SNSPDs. The second process involved suspending the SNSPDs on a thin membrane via a backside etch, where VACNTs were then grown on the backside of the membranes below the nanowires. The membrane style devices showed no degradation in the superconducting properties of the nanowires. Measurements of the membrane style devices before and after the VACNT growth display similar superconducting properties and photon count rates.