Searches for dark matter with liquid xenon time projection chamber experiments have traditionally focused on the region of the parameter space that is characteristic of weakly interacting massive ...particles, ranging from a few GeV / c 2 to a few TeV / c 2 . Models of dark matter with a mass much heavier than this are well motivated by early production mechanisms different from the standard thermal freeze-out, but they have generally been less explored experimentally. In this work, we present a reanalysis of the first science run of the LZ experiment, with an exposure of 0.9 tonne × yr , to search for ultraheavy particle dark matter. The signal topology consists of multiple energy deposits in the active region of the detector forming a straight line, from which the velocity of the incoming particle can be reconstructed on an event-by-event basis. Zero events with this topology were observed after applying the data selection calibrated on a simulated sample of signal-like events. New experimental constraints are derived, which rule out previously unexplored regions of the dark matter parameter space of spin-independent interactions beyond a mass of 10 17 GeV / c 2 . Published by the American Physical Society 2024
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Photodetectors based on organic–inorganic hybrid are promising which can combine the merits like function tunability of organic materials as well as broadband absorption, excitonic ...mechanisms and high carrier mobility of inorganic materials. Flexible thin film photodetectors based on inorganic WSe2 nanosheets and organic PANI by tuning composition are developed by simple, cost effective solution blending process. The fabricated hybrid thin films on filter paper substrate manifest visible light detection with high responsivity, fast photoswitching and high specific detectivity. In addition, the performance of hybrid film is retained even after 400 bending cycles. In case of WSe2-PANI hybrid films, the enhanced photoresponse is due to change in work function between PANI and WSe2 nanosheets, local electric fields are formed at WSe2-PANI interface thereby generating a greater number of photogenerated electrons. Compared with other hybrid-based photodetectors, this work advocates huge development in future applications in wearable electronics, security surveillance, high-performance optoelectronics, etc.
Self-standing polymer materials have gained recognition as a flexible substrate for various optoelectronic devices. Here, we incorporated polyvinyl chloride (PVC) with tungsten diselenide (WSe2) ...microcrystals. The WSe2 microcrystals are added to PVC by solution mixing process. The WSe2-PVC composite film possess excellent flexibility, electrical conductivity of 20 kΩsq−1 at room temperature, high photoresponsivity of 0.3310 mAW−1, detectivity of 1.527 x 109 Jones and external quantum efficiency up to 8.7%. The free-standing WSe2-PVC photodetectors show durability and reproducibility even after 7 months and show stable photoresponse in the bent state. The visible light WSe2-PVC photodetector is sensitive to different monochromatic radiations (470 nm, 540 nm and 670 nm) and demonstrates potential applications in next-generation wearable optoelectronic devices.
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•The microcrystals of WSe2 are grown by direct vapor transport technique.•The free-standing photodetector was prepared by solution mixing process.•The WSe2-PVC photodetector show durability and reproducibility even after 7 months.•The flexible photodetector is sensitive to different monochromatic radiations.
Summary
Pristine WSe2 based electrocatalyst shows poor reaction kinetics in electrochemical hydrogen evolution reaction due to a lack of active atomic sites and an inert basal plane. Herein, we ...report an active system of non‐metallic plasmonic WSe2/WO3−x, supported by highly conductive and eco‐friendly Ag/cellulose paper electrodes. An air thermal annealing technique is used to enrich the p‐WO3−x dopants in WSe2, which is significant for substantially improving electrocatalytic behaviour as well as photo responsive performance in the near‐infrared (NIR) region. The WSe2/WO3−x dramatically decreases the overpotential of HER from −330 to −150 mV (at 10 mA/cm2) owing to homo doping and generation of Se‐vacancies. Surface plasmons resonances of p‐WO3−x give the contributions to injection of photogenerated electrons and overpotential as low as −120 mV can be achieved under the illumination of NIR light. These results represent significant advances in light‐enhanced electrocatalysis and would provide potential applications for commercial hydrogen generation.
Novelty Statement
Novel WSe2/WO3−X hybrid nanosheets‐based electrocatalysts exhibit the light‐enhanced hydrogen evolution reaction. WO3−X enriched WSe2 nanosheets exhibit rapid electrochemical charge transport due to p‐homodoping and Se‐vacancies. Overall, the 3D‐porous structure of cellulose paper and 2D‐ WSe2/WO3−X leads the promising optimisation.
Novel WSe2/WO3−X hybrid nanosheets‐based electrocatalysts exhibit the light‐enhanced hydrogen evolution reaction. WO3−X enriched WSe2 nanosheets exhibit rapid electrochemical charge transport due to p‐homodoping and Se‐vacancies. Overall, the 3D‐porous structure of cellulose paper and 2D‐ WSe2/WO3−X leads the promising optimisation.
Green electronics is a trending and cost-effective method with potential application in health care monitoring and wearable electronics. We present a piezo resistive wearable pressure sensor using ...Polyaniline (PANI) incorporated with cellulose paper (CP) substrate. The ultralow-cost sensor is prepared by coating the sensing material on the paper using simple dip coating method. On stacking multiple PANI-CPs one upon another, the obtained flexible sensor demonstrates excellent sensitivity of 2.23 kPa−1, fast response of 70 ms and wide working range from 2 to 90 kPa. Furthermore, the sensor manifest excellent flexibility, outstanding stability up to 800 loading–unloading cycles and biodegradability. In addition, the pressure sensor can also be used for detecting rapid finger tapping. Apart from the other pressure sensors, this work mainly focusses on fabricating wearable piezo resistive sensors with low cost, facile fabricating process and shows potential for future applications in flexible wearable sensors.
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•Piezo resistive wearable pressure sensor was fabricate using PANI decorated on CP substrate.•The pressure sensor is prepared by coating the sensing material on to the paper using simple dip coating method.•The sensor demonstrates excellent sensitivity of 2.23 kPa−1, fast response of 70 ms and wide working range.•This work mainly focusses on fabricating wearable piezo resistive sensors with low cost, facile fabricating process.
•We fabricated WSe2-PANI nanohybrids for enhanced hydrogen evolution reaction.•WP catalysts exhibited fast HER with over potential as low as of −190 mV at −10 mA/cm2.•This work is based on ...organic-inorganic nanohybrid for effective electro-/photo-catalysis.
In this work, we use the photosensitive WSe2-PANI nanohybrids for enhanced hydrogen evolution reaction. The optimization of chemical composition in catalysts results in rapid catalysis, which is further promoted by the illumination of visible light. The hydrogen evolution is achieved at an over potential as low as −220 mV vs RHE in dark and −190 mV vs RHE in the illuminated condition. WSe2-PANI nanohybrids exhibit stable time-resolved photoresponse with photocurrent of 14.5 mA/cm2 at −350 mV vs RHE under visible light, which corresponds to a photoresponsivity of 0.48 A/W. The light-enhanced hydrogen evolution reaction based on WSe2-PANI nanohybrid electrodes, showcase the substantial progress in the production of energy by using renewable energy sources.
