Eu3+ , Sm3+ Deep-Red Phosphors as Novel Materials for White Light-Emitting Diodes and Simultaneous Performance Enhancement of Organic-Inorganic Perovskite Solar Cells

Possibility to Apply Strontium Aluminate to Produce Light-Emitting Plants: Efficiency and Safety

Light-emitting plants (LEPs) provides light in areas without electricity. The phosphorescent compound was used as a lighting material for LEP development. However, using the phosphorescent compound for LEPs development required optimization and phytotoxicity evaluation. Strontium aluminate (SrAl2 O4 ) is a phosphorescent compound that can glow for a long time and is easily recharged by visible light. In this study, using SrAl2 O4 to develop LEPs was evaluated. Additionally, plant stress under SrAl2 O4 was investigated. Metabolomic analysis can explain the possible mechanism of plants' stress under SrAl2 O4 . After, injecting 3 mL of 5 % (w/v) SrAl2 O4 products 1, 2, and 3 into the stem of Ipomoea aquatica, the result showed that SrAl2 O4 products 2 and 3 caused oxidative stress. The metabolomic analysis also indicated that I. aquatica responded to SrAl2 O4 product 1 by increasing pipecolic acid and salicylic acid, while I. aquatica injected with SrAl2 O4 products 2 and 3 showed a decrease in salicylic acid around 0.005 and 0.061-fold, respectively, compared to control plants. and an excess accumulation of MDA around 10.00-12.00 μmol g-1 FW. A 15 % concentration of SrAl2 O4 can be used for LEPs development, enabling photoemission 18-fold for 50 min. SrAl2 O4 product 1 has the potential to be a material for LEPs.

Computational and optoelectronic quantification of semi-conducting, warm ruby red color emanating Eu3+ complexes with hetro-cyclic ligands

Six Eu³⁺ complexes were synthesised with β-keto acid as main ligand and secondary ligands through liquid assisted grinding method. These complexes were characterised by various techniques such as spectroscopic technique, XRD, EDAX, SEM analysis, thermal technique, Urbach energy and optical band gap investigation. The luminous photophysical properties were studied by PL spectroscopy in solid as well as solution phase and some theoretical calculation was done to investigate the radiative (A_rad) & non-radiative (A_nrad) transition rate, quantum efficiency (ɸ), Judd Ofelt parameters for ⁵D₀ → ⁷F_2,4 transitions in both states. Judd Ofelt parameters were also calculated by the JOES software and the outcomes are well harmonised with theoretical values. The complexes have CIE color coordinate value in ruby red region and above 88.65% color purity in both phases, which made them attractive candidates for red light-emitting displays. ⁵D₀ → ⁷F₂ transition was proposed as a laser emission transition owing to their high branching ratio (67.18-74.24%) in solid and (60.09-74.40%) in solution phase. Computational methods were employed to determine the structure and energy of various molecular orbitals. Antimicrobial assay of complexes was also rationalised and found that the complexes are pertinent as good bactericidal and fungicidal agents in pharmaceutical industry.

Achieving Ultrahigh Efficiency Vacancy-Ordered Double Perovskite Microcrystals via Ionic Liquids

Lead-free perovskites have gained much interest for photovoltaic and optoelectronic applications. But instability and low quantum efficiency significantly limit their prospects for future applications. Here, a general route is reported to synthesize highly stable lead-free perovskites on a large scale with remarkably enhanced quantum efficiency. Two typical vacancy-ordered double perovskites (Cs₂ ZrCl₆ and Cs₂ SnCl₆ ) and their corresponding Bi³⁺ or Sb³⁺ doped samples are synthesized in ionic liquids (ILs) solutions via a simple solution method. These prepared perovskite samples all exhibit high-quality crystalline structures and their photoluminescence quantum yields (PLQYs) all show an increase close to 200% compared to the samples prepared in the hydrochloric acid system. The PLQY of Sb-doped Cs₂ ZrCl₆ with excellent thermal stability can reach up to 90.2%, which is the highest value reported for this system (Cs₂ ZrCl₆ :Sb). Density functional theory calculations reveal that the corresponding interaction between the ILs and the samples can effectively improve the crystal quality and reduce energy loss. The potential applications of the prepared samples for high-performance white light-emitting diodes and optical anti-counterfeiting are also demonstrated. The findings provide a straightforward way to obtain ultrahigh quantum efficiency vacancy-ordered double perovskites with good thermal stability and excellent optoelectronic properties.

Rapid and Large-Scale Preparation of Stable and Efficient White Light Emissive Perovskite Microcrystals Using Ionic Liquids

In this work, we report large-scale preparation of stable Sb³⁺ and Bi³⁺ codoped Cs₂ZrCl₆ microcrystals for highly efficient white light emission using ionic liquids, demonstrating a broad dual-band white emission covering 400-800 nm. The dual emissions originate from the associated self-trapped excitons of the [SbCl₆]^3- and [BiCl₆]^3- octahedra. Moreover, the ratio of the dual-emission peaks can be effectively regulated by tuning the excitation wavelength. Meanwhile, to improve the optical properties and stability, ionic liquids are employed to assist the synthesis process of perovskite materials. The white light emission of one of the samples demonstrates CIE coordinates right in the center of the white light region (0.334, 0.331) and an excellent color rendering index (∼90.3), accompanied by a 66.1% quantum efficiency. Moreover, our method allows the facile synthesis of large batches of microcrystalline powders. Our findings demonstrate the potential of white phosphors as single components for future applications in lighting fields.

Modulating Optical and Electrical Properties of Oxygen Vacancy Enriched La2Ce2O7:Sm3+ Pyrochlore: Role of Dopant Local Structure and Concentration

This work projected the important role of defects in achieving efficient luminescence and electrical conduction in pyrochlore materials. Undoped and Sm3+ doped La2Ce2O7 (LCO and LCOS) stabilize in defect fluorite...

Enhancing upconversion emissions and temperature sensing properties by incorporating Mn2+ for KLu2F7:Yb3+/Er3+ nanocrystals based on thermally and non-thermally coupled levels

Pure phase KLu₂F₇:Yb³⁺/Er³⁺/Mn²⁺ nanocrystals were obtained for which the temperature sensitivity reached up to 45.11 × 10⁻³ K⁻¹ employing non-thermally coupled levels.