1、上转换发光机理及其应用,宋阳 2012-05,Up Conversion Photoluminescence Mechanism and Its Applications,几种基本的上转换过程,一.双光子吸收,二.激发态吸收,几种基本的上转换过程,三.能量共振传递,几种基本的上转换过程,四.光子雪崩,几种基本的上转换过程,五.其他,合作敏化,合作发光,几种基本的上转换过程,In order to observe bimolecular quenching of the triplet excited state of the sensitizer the triplet acceptor en
2、ergy must be lower than the triplet energy of the sensitizer. The greater the energy difference between the triplet sensitizer and triplet acceptor, the greater the driving force for this reaction and generally speaking, the more favorable the triplet energy transfer process. It is also advantageous
3、 to use acceptors/annihilators with near unity fluorescence quantum yields since this value ultimately contributes to the overall upconversion quantum efficiency. The sensitizer (donor) molecule is chosen so that its singlet excited state lies below that of the acceptors singlet manifold while the s
4、ensitizers triplet state lies above that of the acceptor. In essence, the singlet and triplet excited states of the sensitizer should be strategically nested between the singlet and triplet excited states of the acceptor/annihilator. As long as these specific energy criteria are met and the combined
5、 triplet energy from two acceptor molecules is greater than or equal to the acceptors singlet state energy, then conditions are appropriate for the observation of upconverted fluorescence from the sample,TTET-TTA过程,镧系三价离子能级图,实例(1) Yb/Er, Yb/Tm,Journal of Alloy and Compounds Volume 509,Issue 5, 10 February 2011,实例(1)Yb/Er, Yb/Tm,实例(2)Yb/Ho/Ce, Yb/Ho,实例(2)Yb/Ho/Ce, Yb/Ho,实例(3) Gd() 的能量传递,实例(4)Mn()的参与,实例(4)Mn的参与,实例(4)Mn的参与,未完待续。,