HfO2 films codoped with Ce3+ and several concentrations of Dy3+ have been processed by the ultrasonic spray pyrolysis technique. Emissions from Dy3+ ions centred at 480 and 575 nm associated with the 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions, respectively, have been observed upon UV excitation via a non-radiative energy transfer from Ce3+ to Dy3+ ions. Such energy transfer via an electric dipole–quadrupole interaction appears to be the most probable transfer mechanism. The efficiency of this transfer increases up to 86 ± 3% for the film with the highest Dy3+ content (1.9 ± 0.1 at.% as measured from EDS). The possibility of achieving the coordinates of ideal white light with increasing the concentration of dysprosium is demonstrated.
|Titolo:||Blue-yellow photoluminescence from Ce3+ -> Dy3+ energy transfer in HfO2:Ce3+:Dy3+ films deposited by ultrasonic spray pyrolysis|
|Data di pubblicazione:||2011|
|Appare nelle tipologie:||01.01 Articolo in Rivista|