▎ 摘　　要

NOVELTY - Detector comprises at least one tin monochalcogenide nanosheet, and at least two electrodes, where the tin monochalcogenide nanosheets including tin mono-sulfide, or tin mono-selenide. The electrode comprises conductive material of metals, metal alloys, noble metals, carbon, graphite, graphene, carbon nanofibers, carbon nanotubes, fullerenes, molecular wires, conducting polymers, polythiophenes, and polyethylenedioxythiophene, including hybrid and/or composite conductive materials, preferably noble metal e.g. gold. USE - The detector is useful in device which is sensor, or detector module, or detector package, or array of detectors, or microscope, or imaging device, or dose rate measurement device, or real-time dose rate measurement device for detecting x-rays (all claimed) within the water window region. ADVANTAGE - The detector: has peak response of 100 eV-1 keV, preferably 150-900 eV, more preferably 200-600 eV, most preferably ≈ 600 eV; peak sensitivity at bias voltage of 1 V is 0.5x 104-5x 104uCHy(vac)-1cm-2, preferably 1x 104-3x 104uCHy(vac)-1cm-2, more preferably 1.1x 104-2.6x 104uCHy(vac)-1cm-2, most preferably 2.55x 104UCHy(vac)-1cm-2, and on/off transient response times to soft x-rays with photon energies of 100 eV-1 keV; and has rise time of 2-7 mx seconds, fall time of 1-4 mx seconds, average rise time of 3-4 mx seconds, preferably 3.4 mx seconds, and/or average fall time of 2-3 mx seconds, preferably 2.5 mx seconds, on/off transient response times to soft X-rays with a photon energy of 600 eV have rise time of 7 mx seconds and fall time of 2 mx seconds, soft X-rays of photon energies falling of 100 eV-5 keV and soft X-rays are in the water window region of 200-600 eV. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: device comprising at least one detector; fabricating the detector comprising synthesizing tin mono-chalcogenide nanosheet by exposing molten liquid tin to hydrogen chalcogenide gas, and by its producing tin monochalcogenide nanosheet at the surface of the molten liquid tin, where the hydrogen chalcogenide gas is hydrogen sulfide gas and hydrogen selenide gas, exfoliating the tin mono-chalcogenide nanosheet from the surface of the molten liquid tin, transferring the exfoliated tin mono-chalcogenide nanosheet to suitable support substrate, where the support substrate is electrically non-conductive and suitably transparent to x-rays, and providing electrodes in electrical contact with the supported tin mono-chalcogenide nanosheet; and use of tin mono-chalcogenide nanosheets for detecting x-rays.