不同过渡金属离子的特点

Mn²⁺

• The energy transfer from the sensitizer to the Mn²⁺ centers occurs via exchange interaction, requiring a first neighboring position.
• CaZnOS基质中，devidation from a pure tetrahedral symmetry，使得spin and parity selection rule is strongly relaxed，所以发光强. [Philipe_JES_2011]
• 对任何selection rule都是禁戒。[Philipe_JES_2011]
• 多数雷达屏用的都是Mn2+激活的氟化物，它们都有长余辉(100 ms~1 s)或极长余辉(1 s 以上)，比如(Zn,Mg)F₂:Mn²⁺长余辉(橙色光)，(KF, MgF₂): Mn²⁺极长余辉(橙色光)，另外还用Zn₂SiO₄:Mn²⁺,As(长余辉，绿光)。

Mn⁴⁺

• independent of CFS
• dominated by 电子云扩展效应，所以F^-为配体的时候，发红光，O^2-为配体发近红光。
• 好的文章：
  • Understanding the Efficiency of Mn⁴⁺ Phosphors: Study of the Spinel Mg₂Ti_1−xMn_xO₄-JPCC-2021
  • Quenching of the red Mn⁴⁺ luminescence in Mn⁴⁺-doped fluoride LED phosphors-Light-2018

Cr³⁺

• luminescence is highly sensitive to the local surrounding in the host lattice and nearby defects. [Olivier_ECS_2018]
• ususally has a good thermal stability.不用校正TL. [Olivier_ECS_2018]
• lower the crystal field, the more emission from the ⁴T₂ level will contribute to the global emission profile. [Olivier_ECS_2018]
• ⁴T₂能级的发射是宽带(spin-allowed)，而R线(零声子线)窄带发射是spin-forbidden，是来自²E的激发态。
• 以Y₃Al₂Ga₃O₁₂:Cr³⁺为例，在低温的时候(10 K)以窄带发射为主，随着温度的升高，窄带发射减弱，宽带发射增强(总积分强度反而增加，到500K)，但是温度进一步升高的话，宽带发射也减弱。Temperature dependent change in PL spectra is due to thermal expansion of lattice during heating, which results in weaker crystal field of Cr³⁺ ions。所以作者认为不需要将TL进行热猝灭的校正。[Tanabe-OME-2016]
• Ruby激光，红宝石Al₂O₃:Cr³⁺，发射波长为694.3 nm，为最早的固体激光器材料(1960年发现)。可调谐的Cr³⁺掺杂激光晶体目前最好的有:
  • LiCaAlF₆，调谐范围为700~900 nm；
  • LiSrAlF₆，调谐范围为800~1010 nm；
  • LiSrGaF₆，调谐范围为850~950 nm；
    

Cr⁴⁺

Cr⁴⁺掺杂镁橄榄石(Mg₂SiO₄)激光器，调谐范围1350~1500 nm；Cr⁴⁺掺杂的YAG激光器，调谐范围1350~1500 nm。

参考资料：掺Cr⁴⁺离子的激光材料与器件

Ti3+

Al2O3:Ti3+钛宝石激光器，调谐范围为600~1100 nm。

Bi³⁺