We demonstrate nanostructural evolution resulting in highly increased photoluminescence in silicates doped with Er3+ ions. High-resolution transmission electron microscopy (HRTEM) imaging, nano-energy dispersed X-ray (NEDX) spectroscopy, X-ray diffraction (XRD) and photoluminescence analysis confirm the local composition and structure changes of the Er3+ ions upon thermal annealing. We studied two types of amorphous nanopowder: the first is of the composition SiO2/18Al2O3/2Er2O3 (SAE), synthesized by combustion flame-chemical vapor condensation, and the second is with a composition of SiO2/8Y2O3/2Er2O3 (SYE), synthesized by sol-gel synthesis (composition in mol%). Electron diffraction and HRTEM imaging clearly show the formation of nanocrystallites with an average diameter of approximately 8 nm in SAE samples annealed at 1000 degrees C and SYE samples annealed at 1200 degrees C. The volume fraction of the nanocrystalline phase increased with each heat treatment, eventually leading to complete devitrification at 1400 degrees C. Further XRD and NEDX analysis indicates that the nanocrystalline phase has the pyrochlore structure with the formula Er(x)Al(2-x)Si2O7 or Er(x)Y(2-x)Si2O7 and a surrounding silica matrix.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/jmicro/dfi040 | DOI Listing |
Luminescence
January 2025
Department of Physics, IMN, Universidad de La Laguna, San Cristobal de La Laguna, Santa Cruz de Tenerife, Spain.
Er-doped BaF single crystals were investigated with two primary aims: first, to probe the infrared emissions from the I level (around 1.0 μm) under 1500-nm excitation and, second, to use the crystal to enhance the efficiency of silicon-based solar cells through upconversion mechanism. Upon excitation at 1500 nm, the upconversion emission spectrum of the Er-doped BaF single crystals, recorded in the range of 480-1080 nm, exhibited two well-structured visible bands at 538 and 650 nm, along with a strong near infrared emission at 971 nm.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Huzhou Key Laboratory of Materials for Energy Conversion and Storage, College of Science, Huzhou University, Huzhou 313000, China. Electronic address:
1550 nm-responsive upconversion luminescence (UCL) has attracted increasing attention due to its potential applicability in a new generation of bio-probes and photonic devices. However, regulating multi-color UCL with pump power remains a challenge. In this work, through constructing the coupling between Er and Tm ions and suppressing the energy transfer upconversion process of Er ions, the response of UCL color in Gd(MoO):Er/Tm to pump power is enhanced significantly.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Key Laboratory for High Efficiency Energy Conversion Science and Technology of Henan Province, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, School of Physics and Electronics, Henan University, Kaifeng, 475004, P. R. China.
Multimode luminescent materials exhibit tunable photon emissions under different excitation or stimuli channels, endowing them high encoding capacity and confidentiality for anti-counterfeiting and encryption. Achieving multimode luminescence into a stable single material presents a promising but remains a challenge. Here, the downshifting/upconversion emissions, color-tuning persistent luminescence (PersL), temperature-dependent multi-color emissions, and hydrochromism are integrated into Er ions doped CsNaYbCl nanocrystals (NCs) by leveraging shallow defect levels and directed energy migration.
View Article and Find Full Text PDFInorg Chem
January 2025
MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China.
A novel antimonotungstate (AT)-based heterometallic framework {[Er(HO)][Fe(Hpdc)(B-β-SbWO)]}·50HO (, Hpdc = pyridine-2,5-dicarboxylic acid) was obtained through a synergistic strategy of in situ-generated transition-metal-encapsulated polyoxometalate (POM) building units and the substitution reaction. Its structural unit is composed of a tetra-Fe-substituted Krebs-type [Fe(Hpdc)(B-β-SbWO)] subunit and two [Er(HO)] cations. This subunit can be regarded as a product of carboxylic oxygen atoms of Hpdc ligands replacing active water ligands in the [Fe(HO)(B-β-SbWO)] species.
View Article and Find Full Text PDFSmall
January 2025
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310014, P. R. China.
Developing single-particle nanocomposite with aqueous-phase orthogonal multicolor phosphorescence or multimodal luminescence holds great significance for optical coding, anti-counterfeiting encryption, bioimaging, and biosensing. However, it faces challenges such as a limited range of emission wavelengths and difficulties in controlling the synthesis process. In this work, a conjugate structure manipulation integrated luminophor confinement strategy is proposed to prepare carbon dots@upconversion nanoparticles (CDs@UCNPs) featuring aqueous-phase orthogonal multicolor room-temperature phosphorescence-upconversion luminescence (RTP-UCL) through wet-chemical synthetic methods.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!