Abstract: Optical and electronic detection of chemicals, and particularly strong electron-donors, by 2H to 1T phase-based transition metal dichalcogenide (TMD) films, detection apparatus incorporating the TMD films, methods for forming the detection apparatus, and detection systems and methods based on the TMD films are provided. The detection apparatus includes a 2H phase TMD film that transitions to the 1T phase under exposure to strong electron donors. After exposure, the phase state can be determined to assess whether all or a portion of the TMD has undergone a transition from the 2H phase to the 1T phase. Following detection, TMD films in the 1T phase can be converted back to the 2H phase, resulting in a reusable chemical sensor that is selective for strong electron donors.

Abstract: Optical and electronic detection of chemicals, and particularly strong electron-donors, by 2H to 1T phase-based transition metal dichalcogenide (TMD) films, detection apparatus incorporating the TMD films, methods for forming the detection apparatus, and detection systems and methods based on the TMD films are provided. The detection apparatus includes a 2H phase TMD film that transitions to the 1T phase under exposure to strong electron donors. After exposure, the phase state can be determined to assess whether all or a portion of the TMD has undergone a transition from the 2H phase to the 1T phase. Following detection, TMD films in the 1T phase can be converted back to the 2H phase, resulting in a reusable chemical sensor that is selective for strong electron donors.

Abstract: Optical and electronic detection of chemicals, and particularly strong electron-donors, by 2H to 1T phase-based transition metal dichalcogenide (TMD) films, detection apparatus incorporating the TMD films, methods for forming the detection apparatus, and detection systems and methods based on the TMD films are provided. The detection apparatus includes a 2H phase TMD film that transitions to the 1T phase under exposure to strong electron donors. After exposure, the phase state can be determined to assess whether all or a portion of the TMD has undergone a transition from the 2H phase to the 1T phase. Following detection, TMD films in the 1T phase can be converted back to the 2H phase, resulting in a reusable chemical sensor that is selective for strong electron donors.

Abstract: A method of making a low dimensional material chemical vapor sensor comprising providing a monolayer of a transition metal dichalcogenide, applying the monolayer to a substrate, applying a PMMA film, defining trenches, and placing the device in a n-butyl lithium (nbl) bath. A low dimensional material chemical vapor sensor comprising a monolayer of a transition metal dichalcogenide, the monolayer applied to a substrate, a region or regions of the transition metal dichalcogenide that have been treated with n-butyl lithium, the region or regions of the transition metal dichalcogenide that have been treated with n-butyl lithium have transitioned from a semiconducting to metallic phase, metal contacts on the region or regions of the transition metal dichalcogenide that have been treated with the n-butyl lithium.

Abstract: Optical and electronic detection of chemicals, and particularly strong electron-donors, by 2H to 1T phase-based transition metal dichalcogenide (TMD) films, detection apparatus incorporating the TMD films, methods for forming the detection apparatus, and detection systems and methods based on the TMD films are provided. The detection apparatus includes a 2H phase TMD film that transitions to the 1T phase under exposure to strong electron donors. After exposure, the phase state can be determined to assess whether all or a portion of the TMD has undergone a transition from the 2H phase to the 1T phase. Following detection, TMD films in the 1T phase can be converted back to the 2H phase, resulting in a reusable chemical sensor that is selective for strong electron donors.

Abstract: A method of making a low dimensional material chemical vapor sensor comprising providing a monolayer of a transition metal dichalcogenide, applying the monolayer to a substrate, applying a PMMA film, defining trenches, and placing the device in a n-butyl lithium (nbl) bath. A low dimensional material chemical vapor sensor comprising a monolayer of a transition metal dichalcogenide, the monolayer applied to a substrate, a region or regions of the transition metal dichalcogenide that have been treated with n-butyl lithium, the region or regions of the transition metal dichalcogenide that have been treated with n-butyl lithium have transitioned from a semiconducting to metallic phase, metal contacts on the region or regions of the transition metal dichalcogenide that have been treated with the n-butyl lithium.

Abstract: Highly sensitive infrared detectors can be made from superconducting micrrip transmission lines, having a single ground plane, a dielectric substrate on the ground plane, and a thin film path of superconducting oxide on the substrate. These microstrip transmission lines can be fabricated into resonant or non-resonant structures. The detectors operate by detecting changes in a microwave signal transmitted through the microstrip, measures in the amplitude, frequency or time domains. An embodiment of this invention is an asymmetric ring interferometer, with or without a metal segment in the shorter leg of the interferometer. Another embodiment of this invention is a meander path transmission line, which, in certain configurations, may be used as a single element array with very high resolution in the direction parallel to the meander lines.