三价稀土离子在高带隙氟化物基质中超长余辉性质及机理研究

发射在第二生物窗口(1000-1700nm)的 Er3+，Nd3+，Ho3+掺杂的氟化物纳米荧光体是目前最成功的深层组织荧光标识材料，但短的激发波长限制了它的穿透深度，且给手术带来不便。余辉材料不需要激发就能产生光辐射是解决这一问题的有效途径。然而由于其特殊的电子排布Er3+，Nd3+，Ho3+很难实现余辉发射，另外以往余辉材料目的是用于照明和显示，激发源采用汞灯，报道的三价稀土离子余辉材料带隙都较低于5ev，即高带隙余辉材料的研究还是一个待开垦的处女地。申请者首次提出采用X射线等高能射线激发，在高带隙氟化物基质中实现所有三价稀土离子余辉发射，特别是Er3+，Nd3+，Ho3+ 超长红外余辉发射的研究策略。通过这个策略把三价稀土离子余辉材料首次拓宽到基质材料带隙大于5ev的领域，必将刺激更多新型余辉材料的发现。考虑到X射线在肌体组织中无限穿透性，新型红外余辉材料将为深层疾病治疗带来曙光。

Er3+, Nd3+, Ho3+ doped fluoride nanophosphor emitted in the second biological window (1000-1700 nm) is currently the most successful deep tissue bioluminescent labeling material, however, the short excitation wavelength limits its penetration depth and causes inconvenience to the surgery. The afterglow material can generate light radiation without excitation, which is an effective way to solve this problem. However, due to the special electronic arrangement of Er3+, Nd3+, Ho3+, it is difficult to achieve afterglow emission. In addition, since the afterglow materials have been mainly used for illumination and display, the excitation source uses a mercury lamp, the band gap of the afterglow material is usually lower，that is, the study of high band gap afterglow materials (higher than 5ev) is still a virgin land to be reclaimedt. For the first time, the applicant proposed the following research strategy: using high-energy ray excitation such as X-ray to achieve the afterglow emission of all trivalent rare-earths ion in a high band gap fluoride matrix, especially Er3+, Nd3+, Ho3+ ultra-long infrared afterglow emission.Through this strategy, the trivalent rare earth ion afterglow material is first broadened to a region where the band gap of the matrix material is greater than 5 ev, which will certainly stimulate the discovery of more new afterglow materials. Considering the infinite penetration of X-rays in the body tissue, the new infrared afterglow materials will bring dawn to the treatment of deep diseases.