An introduction to the 2nd International Workshop on Persistent and Photostimulable Phosphors (IWPPP 2013)

摘要

"Persistent luminescence", also called as "long lasting phosphorescence" in some cases, has long been known and widely applied in many traditional areas such as emergency signs, night glowing indicators or toys. New emerging applications of deep red persistent phosphors are: (1) in vivo biological optical imaging such as tumor targeting and (2) photodynamic therapy for cancer. It is believed that such technology can avoid tissue autofluorescence efficiently and thereby lead to high sensitive real time imaging for small animals. Originally, it necessitates ex vivo excitation before injection. Latest advance, however, shows the excitation can be done even in vivo by a longer wavelength red light which can penetrate through living tissues. This, thereby, enables the long term imaging in living animals possible. These findings soon turn persistent phosphors into hot research area again. Despite of these brilliant advances, it is awkward that we actually do not fully understand how efficient persistent phosphors can be obtained, what mechanism governs the phenomenon, and how desirable species of defect can be created intentionally rather than accidentally.