Room temperature synthesis, concentration quenching study and defect formation in β-Ag2MoO4:Dy3+- photoluminescence and positron annihilation spectroscopy
Room temperature synthesis, concentration quenching study and defect formation in β-Ag2MoO4:Dy3+- photoluminescence and positron annihilation spectroscopy
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DOI：
10.1016/j.jlumin.2019.04.031
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发表时间：
2019-08
影响因子：
3.6
通讯作者：
K. Sudarshan;S. Gupta;K. Sonawane;R. Kadam
中科院分区：
文献类型：
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作者：
K. Sudarshan;S. Gupta;K. Sonawane;R. Kadam
设计用于固态照明的新材料并了解设计它们所涉及的各种复杂性（例如缺陷、能量转移和浓度猝灭）非常重要。此类材料将在光电、能源和健康产业中发挥巨大作用。本工作朝着这个方向努力，探索在中性条件下使用简单的共沉淀方法室温合成Dy3+掺杂的β-Ag2MoO4。纯β-Ag2MoO4在紫外光照射下呈现蓝-绿光发射。在掺杂 Dy3+ 时，会发生有效的主体-掺杂剂能量转移。浓度猝灭研究揭示了 Dy3+ 掺杂 β-Ag2MoO4 中的非辐射能量转移是通过交换相互作用的 Dexter 机制发生的。此外，在 β-Ag2MoO4a 中掺杂 Dy3+ 离子时，由于主体敏化能量转移引起的蓝色、黄色和红色带的存在，可以观察到多色发射。正电子寿命研究表明 Dy3+ 掺杂会产生阳离子空位。 PL 发射中的正电子寿命和不对称率表明 Dy3+ 在 Ag+ 位点稳定。光致发光寿命光谱显示Dy3+离子的非均匀分布及其周围环境在其附近由于异价掺杂而产生的缺陷方面有所不同。浓度猝灭研究、紫外激发光致发光、缺陷光谱、掺杂离子局部结构和激发态寿命等方面的完整工作表明，所开发的荧光粉有可能用于 LED 应用的固态荧光粉。未来的工作将观察材料特性在进入纳米域时如何变化，并利用 f-f 波段（351nm）使其变得可激发。这种荧光粉的唯一缺点是该区域的吸收较差。
Designing new materials for solid state lighting and understanding the various intricacies involved for designing them such as defects, energy transfer and concentration quenching is very important. Such materials will be highly beneficial in optoelectronics, energy and health industry. In this work, an effort has been taken in that direction by exploring room temperature synthesized Dy3+doped β-Ag2MoO4using simple co-precipitation method under neutral conditions. Pure β-Ag2MoO4showed blue – green emission upon shining with UV light. On doping Dy3+an efficient host-dopant energy transfer takes place. The concentration quenching study revealed non-radiative energy transfer in Dy3+doped β-Ag2MoO4takes place via Dexter mechanism of exchange interaction. Additionally, on doping Dy3+ions in the β-Ag2MoO4a multicolour emission could be observed due to presence of blue, yellow and red bands induced by host sensitized energy transfer. Positron lifetime studies show that the Dy3+doping creates cation vacancies. Positron lifetimes and asymmetry ratios in PL emission show that Dy3+stabilizes at Ag+sites. Photoluminescence Lifetime Spectroscopy revealed non-homogenous distribution of Dy3+ions and its surroundings differ in terms of their vicinity with respect to defects created due to aliovalent doping. Such complete spectrum of work on concentration quenching study, UV excited photoluminescence, defect spectroscopy, local structure of dopant ion and excited state lifetime indicate that the developed phosphor may potentially be used for solid state phosphor for LED application. Future work will be seeing how the material properties change in going to nanodomain and to make it excitable using f-f band (351 nm). The only demerit of this phosphor is the poor absorption in this region.