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Perovskite solar cells (PSCs) have evolved into a viable potential alternative energy source due to their cost-effectiveness and simple fabrication techniques. Despite the immense research interest attracted by PSCs, their rooftop application remains constrained by their low efficiency and hysteretic nature. To address these issues, in this paper, the introduction of silver metallic nanoparticles (AgNPs) with plasmonic effect was achieved by an experimental approach to stimulate the generation and transport of charge carriers, which subsequently results to minimal hysteresis and broadband-enhanced plasmonic devices. Due to the far-field light scattering effect, AgNPs improve the light-trapping of the devices. As a result, electrical characteristics and light absorption are significantly enhanced, leading to broadband increase in photovoltaic performance. With the introduction of one coating cycle of AgNPs, the highest power conversion efficiency (PCE) of the perovskite solar cells increases from a reference value of 4.543 to 10.856%. The fill factor (FF) of such a device was 0.650, the current density (Jsc) was 18.998 mA/cm2, and voltage (Voc) was 0.879 V. This device shows an improvement of ~139.0% in PCE, ~61.7% in FF, ~43.7% in Jsc and ~2.8% in Voc over the pristine device that lacks AgNPs. The findings of this study contribute to further insight and understanding of plasmonic PSCs by offering useful references and recommendations for PSCs with noble metal NPs incorporation. [ABSTRACT FROM AUTHOR]

Perovskite Solar Cells (PSCs) being the most advanced photovoltaic technology today have attracted global attention due to its solution processability and cost effectiveness. In this paper, we reported the performance of perovskite solar cells by integrating Reduced Graphene Oxide (rGO) as a buffer layer. The combined effect of Ultraviolet visible (UV-vis) spectroscopy, X-ray Diffractometer (XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM), Four Point Probe and Solar Simulator were used to explore the absorbance, crystallinity, morphological, resistivity and current voltage behavior of the photoanodes and devices. The rGO was deposited on top the mesoporous Titanium dioxide (m-TiO2) (Device B), on methylammonium lead triiodide (CH3NH3PbI3) perovskite absorber (Device C) and on m-TiO2 & CH3NH3PbI3 perovskite absorber (Device D). The reference device (Device A) was fabricated without rGO as a bench mark for comparison. From the results obtained, the devices with rGO show significant improvement over the device lacking rGO. The reference device gave a Short Circuit Current Density (Jsc) of 8.151 mAcm-2, Open Circuit Voltage (Voc) of 0.575 V, Fill Factor (FF) of 74.4 % and Power Conversion Efficiency (PCE) of 3.49 %. The best performing device was the one with rGO incorporated on both m-TiO2 and CH3NH3PbI3. The device gave a Jsc of 8.737 mAcm-2, Voc of 0.836 V, FF of 68.1% and PCE of 4.98 %. The device experienced an enhancement of ~7.20 % and 42.69 % in Jsc and PCE over the pristine device. This investigation aids the fundamental understanding of the effect of Graphene Materials (GRMs) on the optoelectronic properties of PSCs, and it further confirms the promising prospects of achieving low-cost, efficient and stable PSCs for commercialization with graphene materials. [ABSTRACT FROM AUTHOR]

Two new series of strontium magnesium borate glasses with Dy3+ and Sm3+ activation (both in the concentration range of 0.1–1.0 mol%) were prepared using the standard melt-quenching and characterized. The optical and physical properties of these singly impurity-doped glass series were compared. The optical and physical properties of these glasses were determined in terms of the density, molar volume, optical band gap, absorption and emission intensities, oscillator strength, refractive index and molar polarizability. The XRD analyses confirmed the amorphous nature of the as-quenched samples. The EDX spectra revealed the actual elemental compositions and FESEM images showed the samples homogeneity without cracks. The UV–vis-NIR absorption spectra of the Dy3+- and Sm3+-doped glasses showed nine and ten characteristics bands respectively. The PL spectra of the Dy3+- and Sm3+-doped glasses displayed three ((at 481 nm, blue; 570 nm, yellow; and 661 nm, red) four (559, 596, 643 and 709 nm) significant peaks, respectively. The lasing potentials of the Dy3+- and Sm3+-doped glasses were compared via Judd-Ofelt evaluation. The values of branching ratio and stimulated emission cross-section for the 4F 9/2 → 6H 13/2 transition in Dy3+ and 4G 5/2 → 6H 7/2 transitions in Sm3+ was maximum, indicating their effectiveness towards photonic devices assembly. The studied glasses have demonstrated high viability for the cutting-edge innovations in the solid―state lighting and high gain optical fibre construction. [ABSTRACT FROM AUTHOR]

Some new type of strontium magnesium borate glass system doped with Dy3+ (various contents 0.1, 0.3, 0.5, 0.7 and 1.0 mol%) were produced using the conventional melt-quenching. Obtained glasses were thermally stable, highly transparent, and moisture resistant. As-prepared samples were characterized to determine their spectroscopic traits. The Judd-Ofelt (J-O) intensity Ω λ (λ = 2, 4, 6) and radiative parameters were calculated to validate the experimental results on the optical characteristics. The XRD pattern of the as-quenched samples verified their glassy nature, FESEM images showed uniform textures and EDX analyses detected the presence of appropriate constituents in the host matrix. Glass containing 0.7 mol% of Dy3+ revealed the optimum optical traits where the luminescence emission intensity was attenuated beyond this content. The optical gain for two intense emission transitions (4F 9/2 →6H 15/2 and 4F 9/2 →6H 13/2) was evaluated. The values of Ω λ (λ = 2, 4, 6) determined the ionic nature of the bonding and symmetry environment of the Dy―ligand matrix based on the viscosity and rigidity of the host glass. The 6H 15/2 →6F 11/2 transition was hypersensitive. The ratio of the yellow to blue (Y/B) emission intensity less than unity indicated the lower degree of covalence between Dy3+ and O2− ions thereby makes these glasses effective for the near UV―LEDs. The higher values of the branching ratio (≥ 50 %) and stimulated emission cross-section enabled the proposed glass composition potential for the optical amplifiers and fibres fabrication. The resonant energy transfer and cross-relaxation processes in the Dy3+ were attributed to be responsible for the improved optical features. [ABSTRACT FROM AUTHOR]