Towards information storage by designing both electron and hole detrapping processes in bismuth and lanthanide-doped LiRE(Si,Ge)O4 (RE = Y, Lu) with high charge carrier storage capacity
Towards information storage by designing both electron and hole detrapping processes in bismuth and lanthanide-doped LiRE(Si,Ge)O4 (RE = Y, Lu) with high charge carrier storage capacity
复制标题
DOI：
10.1016/j.cej.2020.124776
复制
发表时间：
2020-11-15
影响因子：
15.1
通讯作者：
Dorenbos, Pieter
中科院分区：
文献类型：
--
作者：
Lyu, Tianshuai;Dorenbos, Pieter
在真空参考结合能 (VRBE) 图的指导下，探索了铋和镧系元素掺杂的 LiRE(Si,Ge)O-4 (RE = Y, Lu) 族化合物中电子和空穴的捕获和解捕获过程。 Tm3+ 电子陷阱与 LiLuSiO4 中的 Ln(3+)（Ln = Ce、Tb 或 Pr）或 Bi3+ 深空穴陷阱相结合。在热释光读出过程中，Tm2+释放的电子与Ln(4+)和Bi4+处的空穴重新结合，产生典型的Ln(3+) 4f-4f或5d-4f发射和Be A带发射。可以通过选择 Ln(3+)（Ln = Tm 或 Sm）以及固定的 Ln(3+) 和/或 Br3+ 掺杂剂对（如 LiLu1-xYxSiO4:0.01Ce(3+),0.01Ln(3+) 和）来调节镧系离子的电子陷阱深度。 LiLu1-xYxSiO4:0.01Bi(3+),0.01Sm(3+)固溶体，通过调整x，得到导带底部的VRBE工程。优化后的LiLu0.5Y0.5SiO4:0.01Ce(3+)、0.005Sm(3+)的热释光(FL)强度比商业X射线BaFBr(I):Eu2+存储荧光粉高约8.5倍。通过将深 Eu3+ 或 Be 电子陷阱与 Ln(3+)（Ln = Tb 或 Pr）或 Bi3+ 相结合，Ln(3+) 和 Bi3+ 似乎充当 LiLuSiO4 中较深的空穴捕获中心。这里的复合是通过空穴释放而不是更常见报道的电子释放来实现的。空穴从 Ln(4+) 和 Bi4+ 中释放出来，与 Eu2+ 或 Bi2+ 上的电子重新结合，产生特征性的 Eu3+ 4f-4f 和 Bi3+ A 带发射。在LiLu1-xYxSiO4 和LiLu0.25Y0.75Si1-yGeyO4:0.01Bi(3+) 固溶体中讨论了通过晶体成分调制调整Ln(3+) 和Bi3+ 空穴陷阱深度。优化后的LiLu0.25Y0.75SiO4:0.01Bi(3+)的TL强度比商业BaFBr(I):Eu2+高约4.4倍。概念验证信息存储将通过X射线或紫外光充电的LiLu0.5Y0.5SiO4:0.01Ce(3+),0.01Sm(3+)和LiLuo(0.25)Y(0.75)SiO(4):0.01Bi(3+)荧光粉分散在硅胶成像板中进行演示。
Guided by vacuum referred binding energy (VRBE) diagrams, both the trapping and detrapping processes of electrons and holes are explored in the bismuth and lanthanide-doped LiRE(Si,Ge)O-4 (RE = Y, Lu) family of compounds. The Tm3+ electron trap has been combined with the deep hole traps of Ln(3+) (Ln = Ce, Tb, or Pr) or Bi3+ in LiLuSiO4. During the thermoluminescence readout, the electrons released from Tm2+ recombine with holes at Ln(4+) and Bi4+ to produce typical Ln(3+) 4f-4f or 5d-4f emission and Be A-band emission. The electron trap depth of lanthanide ions can be tuned by the choice of Ln(3+) (Ln = Tm or Sm), and for fixed pair of Ln(3+) and/or Br3+ dopants like in LiLu1-xYxSiO4:0.01Ce(3+),0.01Ln(3+) and LiLu1-xYxSiO4:0.01Bi(3+),0.01Sm(3+) solid solutions, by adjusting x, resulting in the engineering of the VRBE at the conduction band bottom. The thermoluminescence (FL) intensity of the optimized LiLu0.5Y0.5SiO4:0.01Ce(3+), 0.005Sm(3+) is about 8.5 times higher than that of the com- mercial X-ray BaFBr(I):Eu2+ storage phosphor. By combining deep Eu3+ or Be electron traps with Ln(3+) (Ln = Tb or Pr) or Bi3+, Ln(3+) and Bi3+ appear to act as less deep hole capturing centres in LiLuSiO4. Here the recombination is achieved through hole liberation rather than the more commonly reported electron liberation. The holes are released from Ln(4+) and Bi4+ to recombine with electrons at Eu2+ or Bi2+ to give characteristic Eu3+ 4f-4f and Bi3+ A-band emissions. The tailoring of Ln(3+) and Bi3+ hole trap depths by crystal composition modulation is discussed in LiLu1-xYxSiO4 and LiLu0.25Y0.75Si1-yGeyO4:0.01Bi(3+) solid solutions. The TL, intensity of the optimized LiLu0.25Y0.75SiO4:0.01Bi(3+) is similar to 4.4 times higher than that of the commercial BaFBr(I):Eu2+. Proof-of-concept information storage will be demonstrated with X-ray or UV-light charged LiLu0.5Y0.5SiO4:0.01Ce(3+),0.01Sm(3+) and LiLuo(0.25)Y(0.75)SiO(4):0.01Bi(3+) phosphors dispersed in silicone gel imaging plates.