Photoluminescence properties of Pr3+ doped Bi2ZnOB2O6 microcrystals and PMMA-based composites

Exploring the optical properties of La2Hf2O7:Pr3+ nanoparticles under UV and X-ray excitation for potential lighting and scintillating applications

“…54 It is reported that the blue/green emission is more intense than the red emission in CaTiO 3 , whereas the red emission is more intense than the green emission in Na 5 La(WO 4 ) 4 , Na 5 Y(WO 4 ) 4 , CaTa 2 O 6 , and La 2 Ti 2 O 7 , and the Gd 2 Ti 2 O 7 type pyrochlore structure. 52,54,55 Our La 2 Hf 2 O 7 :Pr 3+ NPs can emit both intense green-blue ( 3 P 0 -3 H 4 ) and red ( 1 D 2 -3 H 4 ) emissions, which are important for inorganic phosphors. It seems replacing Ti 4+ with Hf 4+ in the pyrochlore structure changes the green to red ratio due to the difference in the crystal field induced by the HfO 6 octahedra when compared to TiO 6 .…”

“…For the oxide-based host, it is normally localized around the excited states of the lanthanide ion. 54 Emission quenching from the 3 P 0 state of the Pr 3+ ions depends on the spectral position of the CTS with respect to the 3 P 0 and 1 D 2 states. 54 It is reported that the blue/green emission is more intense than the red emission in CaTiO 3 , whereas the red emission is more intense than the green emission in Na 5 La(WO 4 ) 4 , Na 5 Y(WO 4 ) 4 , CaTa 2 O 6 , and La 2 Ti 2 O 7 , and the Gd 2 Ti 2 O 7 type pyrochlore structure.…”

“…54 Emission quenching from the 3 P 0 state of the Pr 3+ ions depends on the spectral position of the CTS with respect to the 3 P 0 and 1 D 2 states. 54 It is reported that the blue/green emission is more intense than the red emission in CaTiO 3 , whereas the red emission is more intense than the green emission in Na 5 La(WO 4 ) 4 , Na 5 Y(WO 4 ) 4 , CaTa 2 O 6 , and La 2 Ti 2 O 7 , and the Gd 2 Ti 2 O 7 type pyrochlore structure. 52,54,55 Our La 2 Hf 2 O 7 :Pr 3+ NPs can emit both intense green-blue ( 3 P 0 -3 H 4 ) and red ( 1 D 2 -3 H 4 ) emissions, which are important for inorganic phosphors.…”

“…The decay profiles displayed non-exponential behavior, however, the 1 D 2 level decays by three different processes: radiative decay ( 1 D 2 -3 H 4 ), multi-photon relaxation ( 1 D 2 -1 G 2 ), and cross-relaxation induced energy transfer ( 1 D 2 -3 H 4 / 3 H 4 -3 F 3,4 ). 54 This non-exponential behavior is mainly due to crossrelaxation and luminescence quenching. Cross-relaxation is a photophysical phenomenon wherein the excitation energy from an ion decaying from a highly excited state promotes a nearby ion from the ground state to a metastable level.…”

A Strategy for the Synthesis of Oxonitridosilicate Phosphors from Anionic Condensation

“…The low-lying state of the Pr−O CTB has been studied and can be attributed to the case reinforcement of the covalency of the Pr−O bond. 56 Therefore, lower CTB states in nitrides can be observed, considering the stronger covalency of the Pr−N bond. This helps LaSr 4 Si 5 N 9 O 2 :Pr 3+ extend the energy absorption range and makes it more compatible with n-UV and blue LED.…”