The electrical characterization of p-Silicon (Si) and n-Zinc oxide (ZnO) nanorod heterojunction diode has been performed. ZnO nanorods were grown on p-Silicon substrate by the aqueous chemical growth ...(ACG) method. The SEM image revealed high density, vertically aligned hexagonal ZnO nanorods with an average height of about 1.2 μm. Electrical characterization of n-ZnO nanorods/p-Si heterojunction diode was done by current-voltage (I-V), capacitance-voltage (C-V), and conductance-voltage (G-V) measurements at room temperature. The heterojunction exhibited good electrical characteristics with diode-like rectifying behaviour with an ideality factor of 2.7, rectification factor of 52, and barrier height of 0.7 V. Energy band (EB) structure has been studied to investigate the factors responsible for small rectification factor. In order to investigate nonidealities, series resistance and distribution of interface state density (NSS) below the conduction band (CB) were extracted with the help of I-V and C-V and G-V measurements. The series resistances were found to be 0.70, 0.73, and 0.75 KΩ, and density distribution interface states from 8.38 × 1012 to 5.83 × 1011 eV−1 cm−2 were obtained from 0.01 eV to 0.55 eV below the conduction band.
Dye-sensitized solar cells (DSSCs) are made of manganese dioxide (MnO2) and Ag-doped manganese dioxide (Ag-MnO2) counter electrodes (CEs). Herein, MnO2 and Ag-MnO2 were synthesized using the ...hydrothermal method and deposited through the drop casting technique. Electrical characterizations were performed to obtain the fill factor (FF), short-circuit current density (JSC), open-circuit voltage (VOC), and power conversion efficiency (PCE). Frequency- and voltage-dependent impedance spectroscopy were performed to gain an insight into the charge transport characteristics. DSSCs fabricated with a MnO2-coated electrode gave a PCE of 2.86% with a VOC of 0.60 V and a JSC of 8.72 mA/cm2, while DSSCs fabricated with Ag-MnO2 CEs demonstrated a higher PCE of 3.05%, with a VOC of 0.66 v and a JSC of 13.3 mA/cm2. The obtained results indicate that Ag-doped MnO2-coated counter electrodes have the potential to replace expensive Pt=coated counter electrodes.
The aim of this study is to boost the power conversion efficiency of a dye-sensitized solar cell (DSSC) by using the co-sensitization strategy with appropriate natural dyes extracted from ...pomegranate, beetroot and cranberry. The fabricated DSSCs were evaluated using current–voltage characteristics and UV-Vis spectroscopy. The co-sensitized DSSC with beetroot and cranberry showed higher short-circuit current density and power conversion efficiency than their individual dye-based DSSCs. This improvement in the performance is due to the lower aggregation of the dyes, broader absorption in the visible region and lower value of impedance. However, co-sensitized DSSCs of pomegranate with beetroot and cranberry did not show any improvement in performance.
The effect of post-growth annealing treatment of zinc oxide (ZnO) nanorods on the electrical properties of their heterojunction diodes (HJDs) is investigated. ZnO nanorods are synthesized by the ...low-temperature aqueous solution growth technique and annealed at temperatures of 400 and 600°C. The as-grown and annealed nanorods are studied by scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. Electrical characterization of the ZnO/Si heterojunction diode is done by current–voltage (
) and capacitance–voltage (
) measurements at room temperature. The barrier height (
), ideality factor (
), doping concentration and density of interface states (
) are extracted. All HJDs exhibited a nonlinear behavior with rectification factors of 23, 1,596 and 309 at ±5 V for the as-grown, 400 and 600°C-annealed nanorod HJDs, respectively. Barrier heights of 0.81 and 0.63 V are obtained for HJDs of 400 and 600°C-annealed nanorods, respectively. The energy distribution of the interface state density has been investigated and found to be in the range 0.70 × 10
to 1.05 × 10
eV/cm
below the conduction band from
= 0.03 to
= 0.58 eV. The highest density of interface states is observed in HJDs of 600°C-annealed nanorods. Overall improved behavior is observed for the heterojunctions diodes of 400°C-annealed ZnO nanorods.
Improvement in panchromatic light-harvesting and photovoltaic performance is reported for dye-sensitized solar cells by adopting co-sensitization technique by mixing dyes. Betalain and Anthocyanin ...natural dyes are extracted from beetroot and cranberries. All dyes are characterized by UV–Vis and FTIR spectroscopy. Solar cells are fabricated and electrical characterizations are performed. Solar cell sensitized with mixed dyes demonstrated improved performance compared to cells of individual dyes, and yielded short circuit current density, open circuit voltage and fill factor of 0.36 mA/cm2, 0.42 V and 0.51 respectively. Their maximum efficiency is 5.37 and 1.16 times higher than that of individual beetroot and cranberry dye DSSCs respectively. Charge transfer processes are studied by impedance spectroscopy characterizations. The obtained results are in close agreement with commercially available N3 dye DSSC. The results yield that mixing dyes from different natural sources can be a very effective to further improve the performance of DSSCs.
Photoelectrical characterization and impedance spectroscopy are performed for Dye sensitized solar cells (DSSC) fabricated by using natural dye (Pomegranate extract) and metallic dye (N719). Dyes are ...characterized by ultraviolet–visible spectroscopy to study optical properties. Typical photovoltaic behaviors are observed with open circuit voltage of 0.52 and 0.7 V and short circuit current density of 0.34 and 14 mA/cm2 for natural and metallic dyes based cells respectively. From current–voltage (I-V) measurements, fill factor, conversion efficiency and ideality factor are extracted. Electrical properties of the cells are investigated using Mott-Schottky plots. To gain insight into charge transport, voltage and frequency dependent impedance spectroscopy is performed. Photovoltaic performance of cells is evaluated from the trends of recombination resistance and chemical capacitance in the measured impedance spectra. Significant contribution of interface trap states is observed at low frequencies and reversal of the polarity of capacitance from positive to negative values is observed at higher frequencies. The overall behavior of devices is compared. To our knowledge these impedance spectroscopy results for natural dye based solar cell are not reported earlier. Their insight and understanding is important for optimizing various components and interfaces for the development of cost effective commercially available natural dyes based DSSCs.
Plant diseases are a significant yield and quality constraint for farmers around the world due to their severe impact on agricultural productivity. Such losses can have a substantial impact on the ...economy which causes a reduction in farmer's income and higher prices for consumers. Further, it may also result in a severe shortage of food ensuing violent hunger and starvation, especially, in less-developed countries where access to disease prevention methods is limited. This research presents an investigation of Directional Local Quinary Patterns (DLQP) as a feature descriptor for plants leaf disease detection and Support Vector Machine (SVM) as a classifier. The DLQP as a feature descriptor is specifically the first time being used for disease detection in horticulture. DLQP provides directional edge information attending the reference pixel with its neighboring pixel value by involving computation of their grey-level difference based on quinary value (-2, -1, 0, 1, 2) in 0degrees, 45degrees, 90degrees, and 135degrees directions of selected window of plant leaf image. To assess the robustness of DLQP as a texture descriptor we used a research-oriented Plant Village dataset of Tomato plant (3,900 leaf images) comprising of 6 diseased classes, Potato plant (1,526 leaf images) and Apple plant (2,600 leaf images) comprising of 3 diseased classes. The accuracies of 95.6%, 96.2% and 97.8% for the above-mentioned crops, respectively, were achieved which are higher in comparison with classification on the same dataset using other standard feature descriptors like Local Binary Pattern (LBP) and Local Ternary Patterns (LTP). Further, the effectiveness of the proposed method is proven by comparing it with existing algorithms for plant disease phenotyping. Keywords: Binary Patterns, Ternary Patterns, Directional Local Quinary Patterns, Classification, Early & Late Blight, Tomato, Apple, and Potato Disease
Background
DNA barcoding have been considered as a tool to facilitate species identification based on its simplicity and high-level accuracy in compression to the complexity and subjective biases ...linked to morphological identification of taxa. MaturaseK gene (
MatK gene)
of the chloroplast is very vital in the plant system which is involved in the group II intron splicing. The main objective of this study is to determine the relative utility of the “
MatK
” chloroplast gene for barcoding in 15 legume as a tool to facilitate species identification based on their simplicity and high-level accuracy linked to morphological identification of taxa.
Methods and Results
MatK
gene sequences were submitted to GenBank and the accession numbers were obtained with sequence length ranging from 730 to 1545 nucleotides. These DNA sequences were aligned with database sequence using PROMALS server
,
Clustal Omega server and Bioedit program. Maximum likelihood and neighbor-joining algorithms were employed for constructing phylogeny. Overall, these results indicated that the phylogenetic tree analysis and the evolutionary distances of an individual dataset of each species were agreed with a phylogenetic tree of all each other consisting of two clades, the first clade comprising
(Enterolobium contortisiliquum, Albizia lebbek), Acacia saligna
,
Leucaena leucocephala, Dichrostachys Cinerea, (Delonix regia, Parkinsonia aculeata), (Senna surattensis, Cassia fistula, Cassia javanica)
and
Schotia brachypetala
were more closely to each other, respectively. The remaining four species of
Erythrina humeana, (Sophora secundiflora, Dalbergia Sissoo, Tipuana Tipu)
constituted the second clade.
Conclusion
Moreover, their sequences could be successfully utilized in single nucleotide polymorphism or as part of the sequence as DNA fragment analysis utilizing polymerase chain reaction in plant systematic. Therefore,
MatK
gene is considered promising a candidate for DNA barcoding in the plant family Fabaceae and provides a clear relationship between the families.
The optimal auxiliary function method (OAFM) is introduced and used in the analysis of a nonlinear system containing coupled Schrödinger–KdV equations, all within the framework of the Caputo ...operator. The OAFM, known for its efficiency in solving nonlinear issues, is used to obtain approximate solutions for the coupled equations’ complicated dynamics. Numerical and graphical assessments prove the suggested method’s correctness and efficiency. This study contributes to the understanding and analysis of coupled Schrödinger–KdV equations and their many applications by providing insights into the behavior of nonlinear systems within mathematical physics.
The second grade nanofluid flow with Cattaneo-Christov heat flux model by a stretching disk is examined in this paper. The nanofluid flow is characterized with Hall current, Brownian motion and ...thermophoresis influences. Entropy optimization with nonlinear thermal radiation, Joule heating and heat absorption/generation is also presented. The convergence of an analytical approach (HAM) is shown. Variation in the nanofluid flow profiles (velocities, thermal, concentration, total entropy, Bejan number) via influential parameters and number are also presented. Radial velocity, axial velocity and total entropy are enhanced with the Weissenberg number. Axial velocity, tangential velocity and Bejan number are heightened with the Hall parameter. The total entropy profile is enhanced with the Brinkman number, diffusion parameter, magnetic parameter and temperature difference. The Bejan number profile is heightened with the diffusion parameter and temperature difference. Arithmetical values of physical quantities are illustrated in Tables.
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