Host Sensitized NIR emission in Sr 2 CeO 4 :Yb 3+ /Nd 3+ phosphors

This study establishes Sr 2 CeO 2 as a promising host for host-sensitized NIR luminescence and provides new insight into the distinct energy-transfer mechanisms operating for Nd 3+ and Yb 3+ . Identifying Ce 4+ charge-transfer excitation (CET) and the possibility of quantum cutting in the Nd 3+ system offer useful strategies for designing more efficient NIR-emitting phosphors for photonic, sensing, and biomedical applications. Characteristic near infrared luminescence of lanthanide activators is reported for Sr 2 CeO 4 :Yb 3+ /Nd 3+ phosphors. Charge transfer absorption of Ce 4+ followed by energy transfer to the activator induced an excitation band around 330 nm. After doping with lanthanides, the decay of Ce 4+ emission becomes faster. From these changes in lifetime, the efficiency of host sensitization coming from Ce4+absorption was evaluated as of the order of just above 50 %.