Song Ting, Zhang Meng, Liu Yuxue, Yang Jian, Gong Zheng, Yan Hong, Zhu Hancheng, Yan Duanting, Liu Chunguang, Xu Changshan
School of Physics, Northeast Normal University 5268 Renmin Street Changchun 130024 China
RSC Adv. 2018 Mar 19;8(20):10954-10963. doi: 10.1039/c8ra01036f. eCollection 2018 Mar 16.
Spinel-phase ZnGaGe Sn O:Cr (ZGGSO:Cr) nanoparticles with various Sn concentrations were prepared by a hydrothermal method in combination with a post-annealing in vacuum at high temperature. For these nanoparticles, the observed near infrared (NIR) persistent luminescence peaked at ∼697 nm and originates from the E, T (F) → A transitions of Cr and the afterglow time exceeds 800 min. For both the interior and surface Cr ions in the ZGGSO host, it can be found that the increased energy transfer from Cr to the deep trap (anti-site defects, ) after the substitution of Ge by Sn plays a key role in enhancing the persistent luminescence of the ZGGSO:Cr nanoparticles. Strikingly, this energy transfer process can be controlled through the variations in the crystal field strength and the trap depths. Our results suggest that not only Sn substitution can improve bioimaging but also the existence of deep traps in ZGGSO:Cr nanoparticles is helpful for retracing bioimaging at any time.
通过水热法结合高温真空后退火制备了具有不同锡浓度的尖晶石相ZnGaGeSnO:Cr（ZGGSO:Cr）纳米颗粒。对于这些纳米颗粒，观察到的近红外（NIR）持续发光在~697nm处达到峰值，源于Cr的E、T（F）→A跃迁，余辉时间超过800分钟。对于ZGGSO主体中的内部和表面Cr离子，可以发现，用Sn替代Ge后，从Cr到深陷阱（反位缺陷）的能量转移增加，在增强ZGGSO:Cr纳米颗粒的持续发光中起关键作用。引人注目的是，这种能量转移过程可以通过晶体场强度和陷阱深度的变化来控制。我们的结果表明，不仅Sn替代可以改善生物成像，而且ZGGSO:Cr纳米颗粒中深陷阱的存在有助于随时追溯生物成像。
