Tuning green-to-red ratio of Ho3+ Activated YPO4 dual-mode luminescence through Yb3+ sensitized nano phosphors

Yb3+/Ho3+co-doped YPO4 nano phosphors were synthesized by polyol route, which has both up-conversion (UC) and down-conversion (DC) characteristics and excellent luminescent properties. DC peaks were seen at ~460, ~550, and ~650 nm. Switching at ~750 with 300 nm excitation, a very faint P-O charge-transfer (CT) band of the Ho3+ ion and a minute non-radiative resonant energy transfer were observed. We found that YPO4: Yb3+/Ho3+ is an up-converting (UC ) nano phosphor capable of large-scale generation and enhancement of luminescence with green and red emissions.RESULT: Under strong laser irradiation at 980 nm, the up-conversion emission spectrum shows obvious peaks expected for Ho3+ ions at ~550 and ~650 nm. This process produces high-quality nanocrystalline materials with sizes in the range of tens of nm. Considering the results obtained under excitation at 300nm, YPO4:Yb3+/Ho3+ yielded high quantum yield values This finding can be used to manufacture high-efficiency phosphors and demonstrates that the nano-phosphor materials covered by this method have a wide range of applications.