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Significant focus has been directed towards inorganic perovskite solar cells because of their notable capabilities in converting sunlight to electricity effectively, their efficient light absorption, and their suitability for conventional semiconductor manufacturing methods. The identification of the composition of perovskite materials is an ongoing challenge to achieve high performing solar cells. Conventional methods of trial and error frequently prove insufficient, especially when confronted with a multitude of potential candidates. In response to this challenge, the suggestion is to employ a machine-learning strategy for more precise and efficient prediction of the characteristics of new inorganic perovskite materials. This work utilized a dataset sourced from the Materials Project database, consisting of 1528 ABX3 materials with varying halide elements (X = F, Cl, Br, Se) and information regarding their bandgap characteristics, including whether they are direct or indirect. By leveraging data augmentation and machine learning (ML) techniques along with a collection of established bandgap values and structural attributes, our proposed model can accurately and rapidly predict the bandgap of novel materials, while also identifying the key elements that contribute to this property. This information can be used to guide the discovery of new organic perovskite materials with desirable properties. Six different machine learning algorithms, including Logistic Regression (LR), Multi-layer Perceptron (MLP), Decision Tree (DT), Support Vector Machine (SVM), Extreme Gradient Boosting (XGBoost), and Random Forest (RF), were used to predict the direct bandgap of potential perovskite materials for this study. RF yielded the best experimental outcomes according to the following metrics: F1-score, Recall, and Precision, attaining scores of 86%, 85%, and 86%, respectively. This result demonstrates that ML has great potential in accelerating organic perovskites material discovery. [ABSTRACT FROM AUTHOR]

CdO-ZnO nanocomposites were synthesized using a simple solution approach, and several characterization approaches were used to examine the morphological, structural, phase, vibrational, optical, and compositional properties of these CdO-ZnO nanocomposites. The FESEM study revealed the development of aggregates ranging in size from 250 nm to 500 nm. These aggregates were composed of various CdO-ZnO nanoparticle shapes and sizes. XRD investigation revealed hexagonal wurtzite and cubic phases in ZnO and CdO, respectively. The crystal size was 28.06 nm. The band-gap energy of the produced nanocomposites was calculated using UV-Vis analysis and was determined to be 2.55 eV. The CdO-ZnO nanocomposites were employed as a promising material for the effective fluorescence detection of hydrazine and for the quicker photocatalytic degradation of Rhodamine B (RhB) dye. Within 120 min of UV light exposure, the RhB dye was 87.0% degraded in the presence of the CdO-ZnO nanocomposites and the degradation process followed zero-order and pseudo-first-order kinetics. Based on 3σ IUPAC criteria, the limit of detection for fluorescent hydrazine sensing was 28.01 µM. According to the results presented here, CdO-ZnO nanocomposites may function as both a photocatalyst for the breakdown of organic pollutants as well as an effective luminous sensor for the detection of harmful analytes. [ABSTRACT FROM AUTHOR]

Anti-reflective coating (ARC) layers on silicon (Si) solar cells usually play a vital role in the amount of light absorbed into the cell and protect the device from environmental degradation. This paper reports on the thickness optimization of hafnium oxide (HfO2) as an ARC layer for high-performance Si solar cells with PC1D simulation analysis. The deposition of the HfO2 ARC layer on Si cells was carried out with a low-cost sol-gel process followed by spin coating. The thickness of the ARC layer was controlled by varying the spinning speed. The HfO2 ARC with a thickness of 70 nm possessed the lowest average reflectance of 6.33% by covering wavelengths ranging from 400–1000 nm. The different thicknesses of HfO2 ARC layers were used as input parameters in a simulation study to explore the photovoltaic characteristics of Si solar cells. The simulation findings showed that, at 70 nm thickness, Si solar cells had an exceptional external quantum efficiency (EQE) of 98% and a maximum power conversion efficiency (PCE) of 21.15%. The thicknesses of HfO2 ARC considerably impacted the photovoltaic (PV) characteristics of Si solar cells, leading to achieving high-performance solar cells. [ABSTRACT FROM AUTHOR]

Abstract: Well‐crystalline porous cobalt oxide (Co3O4) nanorods (NRs) were synthesized through hydrothermal method and applied as electro‐active electrode material for pseudo‐supercapacitors. At low calcination temperature of 300 °C, the porous and smooth morphology of Co3O4 NRs were obtained whereas, the rod morphology changed to stacks of nanoparticles at high calcination at 500 °C. The Fourier transform infrared (FTIR) and Raman scattering spectroscopies revealed the formation of pure and good crystal quality porous Co3O4 NRs. Brunauer‐Emmett‐Teller (BET) surface area analysis of porous Co3O4 NRs showed the decrease of surface area and pore volume with the increase of calcination temperature. The charge storage ability, cycle stability and ion transport of the synthesized porous Co3O4 NRs electrode were investigated by performing cyclic voltammetry (CV) in 6 M KOH electrolyte. As compared to Co3O4 NRs‐500 °C electrode, the specific capacitance of ∼226.3 Fg−1 at a scan rate of ∼10 mVs−1 was achieved by the fabricated pseudo‐supercapacitors based on porous Co3O4 NRs‐300 °C electrode. The synthesized porous Co3O4 NRs electrode showed excellent stability by maintaining up to ∼76% capacity retention after 5000 cycles. [ABSTRACT FROM AUTHOR]

In this work, the structural, optical, morphological, and sensing features of tungsten oxide (WO3) thin film deposited on a silicon substrate via hot-filament chemical vapor deposition (HFCVD) are described. The experimental characterization tools, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV-Vis), and Fourier transform infra-red (FTIR) spectroscopies, etc., were used to determine the properties of WO3 NPys thin films. The grown WO3 thin film illustrated closely packed porous pyramidal nanostructures (NPys) of improved grain size properties. The diffraction analysis revealed (100) and (200) of WO3 phases, suggesting the classic monoclinic crystal WO3 structure. HFCVD grown WO3 NPys thin film was employed as electro-active electrode for detecting ethylenediamine in 10 mL of 0.1 M phosphate buffer solution (PBS) by varying the ethylenediamine concentrations from 10 μM to 200 μM at room temperature. With a detection of limit (LOD) of ~9.56 μM, and a quick reaction time (10 s), the constructed chemical sensor achieved a high sensitivity of ~161.33 μA μM−1 cm−2. The durability test displayed an excellent stability of electrochemical sensor by maintaining over 90% sensitivity after 4 weeks of operation. This work provides a strategy for a facile preparation of WO3 NPys thin film electrode for sensor applications. [ABSTRACT FROM AUTHOR]

The proposed work reports that ZnO nanoflowers were grown on fluorine-doped tin oxide (FTO) substrates via a solution process at low temperature. The high purity and well-crystalline behavior of ZnO nanoflowers were established by X-ray diffraction. The morphological characteristics of ZnO nanoflowers were clearly revealed that the grown flower structures were in high density with 3D floral structure comprising of small rods assembled as petals. Using UV absorption and Raman spectroscopy, the optical and structural properties of the ZnO nanoflowers were studied. The photoelectrochemical properties of the ZnO nanoflowers were studied by utilizing as a photoanode for the manufacture of dye-sensitized solar cells (DSSCs). The fabricated DSSC with ZnO nanoflowers photoanode attained reasonable overall conversion efficiency of ~1.40% and a short-circuit current density (JSC) of ~4.22 mA cm−2 with an open circuit voltage (VOC) of 0.615 V and a fill factor (FF) of ~0.54. ZnO nanostructures have given rise to possible utilization as an inexpensive and efficient photoanode materials for DSSCs. [ABSTRACT FROM AUTHOR]