Journal of Physical Chemistry C
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2021
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IF 4.126
Sen Yang,Shunfa Gong,Zhilong Zhou,Lifang Wu,Minmin Zhang,Lilin Jiang,Wenzhi Wu
The optical and thermometric properties of bismuth (Bi) and ytterbium (Yb) codoped double perovskite Cs2Ag0.6Na0.4InCl6 microcrystals (MCs) are investigated, which possess high photoluminescence quantum yield and stable broadband spectra from visible to near-infrared (NIR) region. Thermal quenching and dynamic properties are shown using temperature-dependent steady-state photoluminescence (PL) and time-resolved PL (TRPL) techniques, which reveal the transition mechanism from self-trapped excitons (STEs) to Yb dopants. Taking advantage of the diverse thermal quenching of distinct PL between STEs and Yb3+ emissions, an optical thermometer based on the fluorescence intensity ratio is designed in the visible and NIR region, which can provide a self-referenced temperature with high sensitivity. The maximum absolute and relative sensor sensitivities are 0.113 K–1 and 1.66% K–1, respectively. These characteristics all demonstrate that Bi/Yb codoped Cs2Ag0.6Na0.4InCl6 MCs can be excellent and novel luminescent materials for non-contact temperature measurement.
研究领域:
材料科学
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光学
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温度测量
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光致发光
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高影响因子
JOURNAL OF RARE EARTHS
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2024
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IF 5.2
Shujian Wang,Dejian Chen,Jie Hu,Sisi Liang,Kunyuan Xu,Maochun Hong,Haomiao Zhu
Lanthanide ions (Ln 3+ ) doping provides a potential strategy to control over the luminescent properties of lead-free halide double perovskite nanocrystals (DP NCs). However, due to the low energy transfer efficiency between self-trapped exciton (STE) and Ln 3+ ions, the characteristic emissions of Ln 3+ ions are not prominent. Furthermore, the energy transfer mechanism between STE and Ln 3+ ions is also elusive and requires in-depth study. We chose trace Bi 3+ -doped Cs 2 Ag 0.6 Na 0.4 InCl 6– x Br x as a representative DP matrix to demonstrate that by tuning the bromide concentration, the Ln 3+ emission can be greatly enhanced. Such enhanced STE and Ln 3+ ions energy transfer originates from the high covalency of Ln–Br bond, which contributes to improvement of the characteristic emission of Ln 3+ ions. Furthermore, optical spectroscopy reveals that the energy transfer mechanism from DP to Eu 3+ ions is different from all the other doped Ln 3+ ions. The energy transfer from DP to Eu 3+ ions is mostly through Eu–Br charge transfer while the other Ln 3+ ions are excited by energy transfer from STE. The distinct energy transfer mechanism has resulted from the energy separation between the excited energy level of Ln 3+ ions and the bottom of conduction band of DP. With increasing the energy separation, the energy transfer from STE to Ln 3+ ions is less efficient because of the generation of a larger number of phonons and finally becomes impossible for Eu 3+ ions. Our results provide new insight into tuning the energy transfer of Ln 3+ -doped DP NCs.
研究领域:
材料科学
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光学
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DOI
高影响因子
CRYSTENGCOMM
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2026
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IF 2.4
Qi Zheng,Tianyun Du,Chunqian Xu,Xiuxun Han
The development of efficient near-infrared (NIR) luminescent materials excitable by visible light remains a significant challenge for practical applications in bioimaging and sensing. Here, we report a novel sensitization strategy to achieve high-efficiency NIR-II emission in lead-free halide double perovskites. Cr3+/Tm3+ co-doped Cs2Ag0.6Na0.4InCl6 single crystals were synthesized via a hydrothermal method. The introduced Cr3+ ions reside in a tailored weak crystal field of the Na+-alloyed host and exhibit strong absorption in the visible region. Furthermore, energy is effectively transferred from Cr3+ to Tm3+ activators, thereby overcoming the intrinsic limitation of weak f–f absorption in lanthanide ions. This strategy yields a remarkable enhancement of the characteristic Tm3+ emission at 1226 nm. The optimally doped phosphor, Cs2Ag0.6Na0.4InCl6:30% Cr3+/30% Tm3+ (nominal feed ratios; actual doping concentrations: 0.14% for Cr3+ and 1.57% for Tm3+), achieves a high photoluminescence quantum yield (PLQY) of 35.8% under 340 nm excitation. The phosphor demonstrates excellent environmental stability, retaining 86.87% of its initial intensity after 210 days of storage under ambient conditions. A fabricated NIR phosphor-converted light-emitting diode (pc-LED) successfully enables proof-of-concept applications in non-destructive food freshness analysis and deep-tissue imaging. This work provides a fundamental design principle utilizing transition-metal sensitization in engineered perovskite hosts for high-performance, stable, and eco-friendly NIR light sources.
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高影响因子
OPTICAL MATERIALS
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2023
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IF 3.9
Yangxian Huang,Dawei Lan,Guangliang Zhang,Riran Zang,Kunsong Hu,Man Mo,Zhijie Fang,Weijian Li,Haiqing Zhan,Xianquan Ming,Guanhan Huang,Guiliang Li,Minfeng Huang,Feng Zhan
The lead-free double perovskite with low toxicity and good performance stability has attracted much attention in optoelectronic device applications. But their photoluminescence quantum yields (PLQY) are low, which limits their applications. Co-doping and alloying are the most valuable methods to improve its PLQY and stability. In this study, we successfully synthesized Bi 3+ and Fe 3+ co-doped Cs 2 Ag 0.6 Na 0.4 InCl 6 double perovskite using the hydrothermal method , and the emission mechanism was further investigated. Under UV-light excitation, the Cs 2 Ag 0.6 Na 0.4 InCl 6 : Bi 3+ /Fe 3+ shows dual emission. This emission results from the modification effect of self-trapped exciton (STE) formation, and Fe 3+ induces longer wavelength emission. By changing the doping contents of Bi 3+ and Fe 3+ , the revolution of double perovskite color from yellow to orange-red can be observed, and its PLQY is up to 39.95%. The studies of the PL emission mechanism reveal that energy transfer occurs between the STE and Fe 3+ , and different doping contents can affect this transfer mechanism. This work has implications for producing double perovskite for optoelectronic semiconductors and provides direction for designing new lead-free double perovskites.
研究领域:
材料科学
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光学
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DOI
高影响因子
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