The emission and the excitation spectra of GdPO4 : Eu^3+ and GdBO3: Eu^3 + prepared by solid state reaction method were investigated using the synchrotron radiation source of SUPERLUMI station of HASYLAB. The ener...The emission and the excitation spectra of GdPO4 : Eu^3+ and GdBO3: Eu^3 + prepared by solid state reaction method were investigated using the synchrotron radiation source of SUPERLUMI station of HASYLAB. The energy transfer between Gd^3+ and Eu^3+ was discussed with the probability of quantum cutting process. In the excitation spectra monitoring the red emission from Eu^3+ , the distinct lines corresponding to the intraconfigurational 4f-4f transitions from Gd^3+ were observed for both samples, indicating an efficient energy transfer from host Gd^3+ ions to the doped Eu^3+ ions. The efficient energy transfer is necessary for the quantum cutting process based on the two-step energy transfer from Gd^3+ to Eu^3+ . However, the overlapping of the lines corresponding to Gd^3+ :^8S7/2→^6GJ and the broad excitation band (180 - 270 nm) due to Eu^3+- O^2- charge transfer states (CTS) around 200 nm cause excitation energy on ^6GJ levels to dissipate into CTS by direct energy transfer, unfavorable to the cross relaxation energy transfer between Gd^3+ and Eu^3+, thus unfavorable to the quantum cutting process. With the help of the general rules governing the energy positions of Eu^3+-O^2- :CTS, the suggestions concerning searching suitable oxide hosts for Gd^3+-Eu^3+ quantum cutting were made.展开更多
文摘The emission and the excitation spectra of GdPO4 : Eu^3+ and GdBO3: Eu^3 + prepared by solid state reaction method were investigated using the synchrotron radiation source of SUPERLUMI station of HASYLAB. The energy transfer between Gd^3+ and Eu^3+ was discussed with the probability of quantum cutting process. In the excitation spectra monitoring the red emission from Eu^3+ , the distinct lines corresponding to the intraconfigurational 4f-4f transitions from Gd^3+ were observed for both samples, indicating an efficient energy transfer from host Gd^3+ ions to the doped Eu^3+ ions. The efficient energy transfer is necessary for the quantum cutting process based on the two-step energy transfer from Gd^3+ to Eu^3+ . However, the overlapping of the lines corresponding to Gd^3+ :^8S7/2→^6GJ and the broad excitation band (180 - 270 nm) due to Eu^3+- O^2- charge transfer states (CTS) around 200 nm cause excitation energy on ^6GJ levels to dissipate into CTS by direct energy transfer, unfavorable to the cross relaxation energy transfer between Gd^3+ and Eu^3+, thus unfavorable to the quantum cutting process. With the help of the general rules governing the energy positions of Eu^3+-O^2- :CTS, the suggestions concerning searching suitable oxide hosts for Gd^3+-Eu^3+ quantum cutting were made.