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Nitrogen dioxide (NO2) is one of the most harmful and highly toxic gas, and it is continuously released into the environment from automotive emissions, industrial emissions, and agriculture activities. According to the American Conference of Governmental Industrial Hygienists (ACGIH), the threshold limit value (TLV) of NO2 is up to 3 ppm for 8 h time-weighted average and 5 ppm for 15 min period. Therefore, the efficient detection of low concentration of NO2 gas is significant for monitoring human health in the near above-mentioned sources. In this aspect, transition metal dichalcogenides (TMDs) based gas sensor holds a promising potential for detecting the toxic gas due to their inherent properties such as, high surface to volume ratio and small intrinsic dimension. Among TMDs, tin disulfide (SnS2) has become a promising sensing material in gas sensing applications, owing to its physical affinity, planar crystal structure, and high specific surface area. Herein, SnS2 was synthesized by hydrothermal method and characterized by X-ray diffraction (XRD) and Raman spectroscopy. Subsequently, the chemiresistive gas sensor was fabricated by depositing SnS2 on the glass substrate which has gold (Au) interdigitated electrode pattern. The fabricated sensor was explored for detecting various gases such as CO, CO2, SO2, NH3, and NO2 at different temperatures (27°C, 60°C, 100°C, 150°C, 200°C, and 250°C) and a maximum response of 24.5% was obtained for 6 ppm NO2 gas at a temperature of 100°C, which demonstrates that the sensor is a highly selective among the other gases. Furthermore, the sensor was utilized to detect the range of NO2 concentrations from 1.5 ppm to 6 ppm at an optimum temperature of 100°C and the results revealed that the experimental detection limit is 1.5 ppm, and the response of the sensor was also observed to be a power law behavior. In addition, the plausible sensing mechanism was explored by use of surface charge transfer to NO2 gas and energy barrie

Organic solar cells in ternary architecture have gained recent importance owing to their superior photovoltaic performances. In this work, we report fabrication and characterization of thermally evaporated small molecule based ternary bulk hetero junction (BHJ) organic photovoltaic (OPV) cells. To this we have used DTDCTB as a donor material, ICBA and C70 are used as electron acceptors in the active layer. The fabricated ternary OPV devices were tested under AM 1.5 solar irradiation. The fabricated devices were optimized for better performance at different annealing temperatures. Ternary device DTDCTB:C70: ICBA (1:0.2:1) presented the best efficiency of 4.68% when annealed at 90°C for 30 minutes. The obtained ternary OPV results were compared with the binary host system and reported efficient ternary OPVs and they are batch to batch reproducible. © 2021 IEEE.

Selective gas leakage detection is crucial due to the adverse effects of harmful gases present in the air on human health. However, existing high-temperature metal oxide gas sensors, which consume more power, are nonspecific and more sensors are required to discriminate different gases. On the other hand, room temperature gas sensors suffer from slow response and poor reliability despite their low power consumption. We proposed a method to discriminate three gases at relatively low power consumption with a single metal oxide gas sensor using temperature sweeping to address these issues. The machine learning classification algorithms in conjunction with the ternary logic of the sensor response at different temperatures were utilized to discriminate the gases. As the proposed approach requires just one metal oxide gas sensor instead of an array consisting of at least three nonspecific sensors to discriminate the multiple gases, the power consumption can be reduced significantly. As a feasible solution to the existing issues of conventional sensors, this novel methodology paves the way for the widespread use of the sensors in practical applications where reduction of power consumption is necessary.

In this work, we report the synthesis and electrical characterization of electrospun manganese III oxide (Mn2O3) nanofibers and their application in chemiresistive biosensing. Here, the Mn2O3 nanofibers, which are inherently p-type semiconductors with a direct bandgap in the order of 1.2-1.4 eV, are drop cast across interdigitated electrodes to create the desired chemiresistive networks. Their I-V characteristics are governed by space charge limited current, attributing to nonlinear behavior at higher voltages. However, in the range of ±0.5 V, near-linear behavior is observed. Here, we have used an analogous R-C network to explain the low- and high-frequency behavior of the said nanofibers under different applied-bias conditions. Furthermore, the effect of temperature on the said nanofibers' conductive properties is investigated, and the corresponding Arrhenius activation energy is derived. We have also explored the conductance-temperature dependence concerning the nanofiber network and have analyzed the potential carrier transport mechanisms. Also, operating in the near-linearity window, we have developed a chemiresistive protocol for DNA sensing. Mn2O3 nanofibers decorated with single-stranded probe DNAs act as transducers for surface hybridization with target nucleotides. The DNA sensing carried out in this work has a dynamic concentration range of 10 fM to 10 nM, with a linear response between 100 pM and 10 nM. © 2021 IEEE.

Gas detection is attaining significant attention in the healthcare sector due to the health issues involved with the inhalation of toxic gases present in the air. Though the existing sensors can efficiently detect the target gases, they suffer from high power consumption, interference with other gases, and baseline drift. Here, we present a drift-independent technique to achieve selectivity and low power consumption with a single unfunctionalized metal oxide gas sensor. We utilized adsorption-desorption noise to discriminate H2S from NH3 and CO2. As it addresses typical challenges of existing resistive gas sensors, the proposed methodology paves the way for developing future low-power selective gas sensing technology.

In this paper, we are reporting for the first time, the piezosensing characterisations of the SiC thin film on silicon, synthesized from boron containing Liquid Polycarbosilane (PCS) as a precursor deposited by Modified Chemical Vapour Deposition (MoCVD) technique followed by the structural characterisation of the film. Comparison was done on the result of the both undoped and doped SiC thin film to highlight the effect of boron doping on the piezo property of the SiC. Interestingly, it was observed that piezoelectric coefficient (d33) of the boron doped SiC thin film was substantially higher (21.33 pm/V) than the undoped SiC thin film (16.21 pm/V). The enhancement in d33 was analysed considering the polarisation inside the thin film created by boron doping. The result shows a promising boron doped SiC thin film material for the application in high temperature piezo sensors.

La0.7Sr0.3MnO3 as a sensing material has shown an amazing potential for uncooled thermal imaging application. Here we report the fabrication of a La0.7Sr0.3MnO3 (LSMO) thin film thermistor on a Si wafer and explored two prime figure-of-merit such as temperature coefficient of resistance (TCR) and optical responsivity, which are very useful parameters to compare the performance with any thermal sensor. The LSMO films were deposited on a SrTiO3(STO) buffer layer with Si/SiO2 as a substrate, by a pulsed laser deposition (PLD) technique. The crystallinity and surface topography of the films were analyzed by X-ray diffraction (XRD) and atomic force microscopy (AFM). The fabricated device was then analyzed for its thermal and electrical characteristics to validate its suitability as an IR sensor. The fabricated device shows very sharp metal-to-insulator (TMI) phase transition temperature at 150 K and very high TCR of +4% K-1 and-4%K-1near 100 K and 200 K respectively, when the temperature was sweeped from 10 K to 300 K. Fabricated Thermistor shows very good thermal response and recovery when subjected to an alternating on-off cycle of IR lamp (150 W) illumination, which confirms its suitability for the highspeed thermal imaging application. The experimental analysis shows highest responsivity of ∼ 21085 V/W at 8.5 μm, which falls in the Long-Wave Infrared (LWIR) region, which is an ideal IR band for any thermal imaging application.