PbS-ZnO Solar Cell: A Numerical Simulation

Nanoscale PbS, especially quantum dots (QDs) are of interest in applications, such as, solar cells and photodetectors because of tunability of band gap from 0.5 to 3 eV. Recently, ZnO/PbS solar cells with 8.55 % conversion efficiency have been reported with films made deposited from ligand exchanged PbS QDs. However, nanocrystalline PbS is easier to fabricate than QDs. This paper reports theoretical investigation into the use of nanocrystalline PbS in place of QDs as solar cell absorber. Solar cells with a structure of SLG/ITO/ZnO or CdS/PbS/Al was simulated using SCAPS software. We have used two n-type materials one is ZnO and second is CdS. The comparative simulated device performance was studied by currentvoltage (I-V) characteristics and quantum efficiency (QE). The final results reveal a power conversion efficiency of 18.5 % for solar cells with p-PbS as absorber and n-ZnO as buffer and 16.8 % for n-CdS buffer layer

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Enhancing Dye Degradation Property of MoO3 Nanoplates by Vanadium Doping

Nanomaterial based water degradation is becoming as a promising option in comparison to conventional water degradation methods. MoO _3 nanoparticles have been used as a nano adsorbent for methylene blue (MB) removal from aqueous solution. Here, effect of vanadium (V) element doping in MoO _3 on adsorption activity against MB was studied. 2%, 4%, 6% and 8% of V element doped MoO _3 nanoparticles were synthesized using surfactant free chemical method. All the synthesized nanoparticles were well characterized through different analysis tools to study their structural, morphological, and optical properties. Stability of particles in water with respect to time was also studied by zeta potential. Adsorption activity of all the samples were carried out and 8% doped MoO _3 nanoparticle was found to be most efficient. Moreover, the regeneration and reusability test of 8% doped MoO _3 nanoparticle was also successfully carried out