Abstract A series of Ce3+, Tb3+ and Yb3+ tri-doped feldspar CaAl2Si2O8 (CASO) phosphors have been successfully synthesized at ∼ 1350 °C under reducing atmosphere. Optical properties of these phosphors have been investigated as a function of doping concentrations by using fluorescence spectra and decay lifetime analysis in detail. The XRD patterns and structure refinements indicate that the dopants do not change the phase structure of host lattice. For Ce3+/Tb3+/Yb3+ all occupied at Ca2+ sites, charge compensation requires cationic vacancies ( V C a / / ) to maintain electrical neutrality instead of oxygen at interstitial site ( O i 2 − ) because the phosphors were synthesized under reducing atmosphere. The near ultraviolet (n-UV) converted to near-infrared (NIR) emission of the aluminosilicate phosphors have achieved via Ce3+ → Tb3+ → Yb3+ resonant energy transfer (ET), enabling their potential application as down-conversion (DC) converter in Si-based solar cells. The role of Tb3+ is acting as ET bridge to connect Ce3+ and Yb3+ ion pairs. Through adjusting optimal doping concentrations, these NIR DC phosphors can exhibit excitation bands in n-UV region and strong NIR emissions.

中文翻译：

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下转换铝硅酸盐荧光粉 CaAl2Si2O8:Ce/Tb/Yb 的结构和光学性能研究

摘要 一系列 Ce3+、Tb3+ 和 Yb3+ 三掺杂长石 CaAl2Si2O8 (CASO) 荧光粉已在 1350 °C 还原气氛下成功合成。通过详细使用荧光光谱和衰变寿命分析，已经研究了这些磷光体的光学特性作为掺杂浓度的函数。XRD 图案和结构改进表明掺杂剂不会改变主晶格的相结构。对于都占据 Ca2+ 位点的 Ce3+/Tb3+/Yb3+，电荷补偿需要阳离子空位 (VC a // ) 来维持电中性而不是间隙位点 (O i 2 - ) 处的氧，因为荧光粉是在还原气氛下合成的。通过 Ce3+ → Tb3+ → Yb3+ 共振能量转移 (ET) 实现了将铝硅酸盐磷光体的近紫外 (n-UV) 转换为近红外 (NIR) 发射，使其成为 Si 中的下变频 (DC) 转换器的潜在应用- 基于太阳能电池。Tb3+ 的作用是作为 ET 桥连接 Ce3+ 和 Yb3+ 离子对。通过调整最佳掺杂浓度，这些 NIR DC 荧光粉可以在 n-UV 区域显示激发带和强 NIR 发射。