Coded within Wien2K, we carry out DFT-based calculations for investigations of the structural, elastic, optoelectronic, and thermoelectric properties of BaXF₃ (X = Co, Ir) fluoro-perovskites. The Birch-Murnaghan fit to the energy-vs-volume data and formation energy shows that these fluoro-perovskites are structurally stable. The phonon calculation confirms the thermodynamic stability, while the relation between elastic constants such as C ₁₁ - C ₁₂ > 0, C ₁₁ > 0, C ₁₁ + 2C ₁₂ > 0, and B > 0 validates the mechanical stability of the compounds. BaIrF₃ exhibits a strong ability to endure compressive and shear stresses. BaCoF₃ shows a weaker capacity of withstanding changes in volume, attributed to a lower bulk modulus. Demonstrating a higher G-modulus of rigidity than the BaIrF₃, BaCoF₃ demonstrates stronger resistance to change the shape and both compounds are found to be anisotropic and brittle. The determined band structure profiles reveal that both BaCoF₃ and BaIrF₃ demonstrate a metallic nature. In addition, the metallic nature of BaCoF₃ and BaIrF₃ is reinforced by the density-of-states (DOS) study, where Co and F atoms contribute significantly to the total DOS in the valence band in the case of BaCoF₃, while that of BaIrF₃ is predominated by the Ba and F atoms. The computed values of ε₁(0) for BaCoF₃ and BaIrF₃ are approximately 30 and 19, respectively, which are in line with Penn's model. The researched materials are confirmed to be strong contenders for optoelectronics by the lack of absorption in the visible range. For their potential use in thermoelectric device applications, thermoelectric parameters such as temperature-dependent Seebeck coefficient, specific heat capacity, thermal conductivity, power factor, and figure of merit are also investigated, which show that these materials are thermally stable and promising for applications in thermoelectric devices.

Biogenic nanoparticles are considered effective alternatives to chemical pesticides for the management of pathogenic plant diseases. This study was focused on the synthesis of stable silver nanoparticles (AgNPs) to control challenging plant pathogenic bacteria in vitro and in planta. We synthesized AgNPs by reacting different proportions of silver nitrate and aqueous extract of Hedera nepalensis. The physicochemical properties of the synthesized AgNPs were determined by using various physical techniques. The TEM analysis revealed the AgNPs less than 50 nm in size and spherical shaped. For antibacterial assays, different concentrations (1000–15.62 µg/mL, 2-fold dilutions) of the extract-free AgNPs (Ef-AgNPs) or extract-mixed AgNPs (Em-AgNPs), and fruit extracts (FE) were used against plant pathogenic bacteria Erwinia carotovora subsp. carotovora, Erwinia carotovora subsp. atroseptica, and Ralstonia solanacearum. In the in vitro assays, we found significant inhibition of both bacterial species in response to maximum concentrations of AgNPs. Overall, Ef-AgNPs exhibited a higher percent inhibition of bacterial pathogens. In potato tubers assay, complete inhibition of Erwinia carotovora was observed, except for the lowest AgNPs concentration of 15.62 µg/mL. Similarly, exposure of tomato plants to Ralstonia solanacearum suspensions (OD600 = 0.2) in the soil-drenching experiment and post-exposure treatment with 1000 µg/mL and 125 µg/mL of AgNPs resulted in disease inhibition. This study provides the basis that biogenic nanoparticles prepared from Hedera nepalensis are one of the best substitutes to synthetic pesticide, having displayed better results to control the growth of phytopathogenic microbes. However, field studies need to be conducted in a controlled environment to scale up the current work and find out the efficacy of nanoparticles on a larger scale.

Semiconductor quantum dots (QDs), being an auspicious outcome of nanotechnology, have wide technological applications based on their simple synthetic procedures, tunable photoluminescent properties, and effective optical stability. However, their utilization in sensing, imaging, and optoelectronic applications is limited due to their intrinsic drawback of fluorescence intermittency, which not only hinders precise biological imaging due to challenges in tracking individual target molecules but also gives inaccurate measurements and creates complications in data analysis due to long dark (off) states that remain on the time scale of milliseconds to minutes. In order to resolve this problem, research work is being carried out on a large scale to elucidate the mechanism following blinking and approaches to suppress it. This review explicitly highlights the key mechanisms: A type (Auger), B type, near band edge carrier (C type), and D type, responsible for the blinking effect in QDs, and explores the effective methods for its suppression including shell engineering, halide vacancy filling, and passivating the surface with ligands, polymers, noble metals, and plasmonic as well as N-Type semiconductor substrates to enhance their efficiency on practical grounds. Nearly non-blinking QDs with an on-state for 99% of the time have been synthesized by shell engineering. The suppression of blinking leads to improved performance and enhanced efficiency of QD-based devices. According to the literature reports, these methodologies efficiently suppress the blinking phenomenon, even approaching near unity (≈1) photoluminescence quantum yield, which is notable. Finally, the current review discusses the advantages of blinking suppression specifically in biomedical applications such as single particle tracking, in vivo and in vitro imaging, and biosensing.