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Mn2O3 nanomaterials have been recently composing a variety of electrochemical systems like fuel cells, supercapacitors, etc., due to their high specific capacitance, low cost, abundance and environmentally benign nature. In this work, mesoporous Mn2O3 nanoparticles (NPs) were synthesized by manganese acetate, citric acid and sodium hydroxide through a hydrothermal process at 150 °C for 3 h. The synthesized mesoporous Mn2O3 NPs were thoroughly characterized in terms of their morphology, surfaces, as well as their crystalline, electrochemical and electrochemical properties. For supercapacitor applications, the synthesized mesoporous Mn2O3 NP-based electrode accomplished an excellent specific capacitance (Csp) of 460 F·g−1 at 10 mV·s−1 with a good electrocatalytic activity by observing good electrochemical properties in a 6 M KOH electrolyte. The excellent Csp might be explained by the improvement of the surface area, porous surface and uniformity, which might favor the generation of large active sites and a fast ionic transport over the good electrocatalytic surface of the Mn2O3 electrode. The fabricated supercapacitors exhibited a good cycling stability after 5000 cycles by maintaining ~83% of Csp.

This paper describes the unique antireflection (AR) layer of vertically arranged ZnO nanorods (NRs) on crystalline silicon (c-Si) solar cells and studies the charge transport and photovoltaic properties by simulation. The vertically arranged ZnO NRs were deposited on ZnO-seeded c-Si wafers by a simple low-temperature solution process. The lengths of the ZnO NRs were optimized by changing the reaction times. Highly dense and vertically arranged ZnO NRs were obtained over the c-Si wafer when the reaction time was 5 h. The deposited ZnO NRs on the c-Si wafers exhibited the lowest reflectance of ~7.5% at 838 nm, having a reasonable average reflectance of ~9.5% in the whole wavelength range (400–1000 nm). Using PC1D software, the charge transport and photovoltaic properties of c-Si solar cells were explored by considering the lengths of the ZnO NRs and the reflectance values. The 1.1 μm length of the ZnO NRs and a minimum average reflectance of 9.5% appeared to be the optimum values for achieving the highest power conversion efficiency of 14.88%. The simulation study for the vertically arranged ZnO NRs AR layers clearly reflects that the low-temperature deposited ZnO NRs on c-Si solar cells could pose a greater prospect in the manufacturing of low-cost c-Si solar cells.

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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.