Search

This work reports on efforts to enhance the photovoltaic performance of standard p‐type monocrystalline silicon solar cell (mono‐Si) through the application of ultraviolet spectral down‐converting phosphors. Terbium‐doped gadolinium oxysulfide phosphor and undoped‐gadolinium oxysulfide precursor powders were prepared by a controlled hydrothermal decomposition of a urea homogeneous precipitation method. The resulting rare‐earth element hydroxycarbonate precursor powders were then converted to the oxysulfide by annealing at 900°C in a sulfur atmosphere. The as‐prepared phosphors were encapsulated in ethylene vinyl acetate co‐polymer resin and applied on the textured surface of solar cell using rotary screen printing. Comparative results from X‐ray powder diffraction, field emission scanning electron microscopy, scanning transmission electron microscopy, and photoluminescence spectroscopy studies on the microstructure and luminescent properties of the materials are reported. We also compared the optical reflectance and external quantum efficiency response of the cells with and without a luminescent phosphor layer. The results obtained on the terbium‐doped gadolinium oxysulfide phosphor show clearly that the down‐conversion effect induced by the terbium dopant play a crucial role in enhancing the photovoltaic cells' performance. Under an empirical one‐sun illumination, the modified cells showed an optimum enhancement of 3.6% (from 16.43% to 17.02%) in conversion efficiency relative to bare cells. In the concentration range of 1 to 2.5 mg/mL, EVA/Gd2O2S (blank) composites also improve electrical efficiency, but not as much as EVA/Gd2O2S:Tb3+ composites. [ABSTRACT FROM AUTHOR]

Summary: This study looks at investigating the influence of high surface area TiO2 and MgO‐doped TiO2 aerogel nanomaterials to improve the photovoltaic performance of monocrystalline silicon (mono‐Si) solar cells. TiO2 and MgO‐doped TiO2 anatase nanoaerogels were synthesized via a single‐step colloidal homogeneous precipitation sol‐gel method in a compact high‐pressure hydrogen reactor. TiO2‐based nanoparticles were encapsulated in ethylene vinyl acetate resins, and the obtained composite solutions were screen printed on the textured surface of the cells. The specific surface area, microstructural, composition, and optical properties of the nanoaerogels were characterized by Brunaur‐Emmett‐Teller, X‐ray powder diffractometer, energy‐dispersive X‐ray spectroscopy, field emission transmission electron microscope, field emission scanning electron microscope, and ultraviolet‐visible spectrophotometry. We observed that the MgO‐doped TiO2 (2% mol) nanoaerogel exhibited a much superior specific surface area (231 m2/g) compared with the undoped TiO2 (154 m2/g). Experimental results showed that the calculated relative power conversion efficiency increased by 4.6% for the MgO‐doped TiO2 coating and 3.4% for the undoped TiO2 under a simulated one‐sun illumination. [ABSTRACT FROM AUTHOR]

The present work involves the development of a novel method for the fabrication of zirconium nickel (Zr(x)Ni(y)) alloy used as a nanocatalyst to improve the hydrogen storage properties of the Mg/MgH2 system. The catalyst was fabricated through the high-pressure reactor and activated under hydrogen prior to being mechanically milled with the MgH2 for 5 h under argon. The microstructure characterisation of the samples was determined via SEM-EDX (scanning electron microscope analysis–energy dispersive X-ray spectroscopy), XRD (X-ray diffraction) and FE-HRTEM (field emission high resolution transmission electron microscopy), and the desorption characteristic of the nanocomposite (10 wt.% Zr(x)Ni(y)–MgH2) was determined via TPD (temperature-programmed desorption). The nanostructured MgH2 powder milled with 10 wt.% of the activated Zr(x)Ni(y) based nanocatalyst resulted in a faster hydrogen release—5.9 H2-wt.% at onset temperature 210 °C/peak temperature 232 °C. The observed significant improvement in the hydrogen desorption properties was likely to be the result of the impact of the highly dispersed catalyst on the surface of the Mg/MgH2 system, the reduction in particle size during the ball milling process and/or the formation of Mg0.996Zr0.004 phase during the milling process. [ABSTRACT FROM AUTHOR]