Photoluminescence properties of Tb³⁺ doped BiPO₄ nanophosphor synthesised by co-precipitation method using ethylene glycol

ABSTRACT

This work investigated the photoluminescence behaviour of Tb³⁺ doped BiPO₄ nanophosphors synthesised by co-precipitation method using ethylene glycol. The prepared nanophosphors were characterised by XRD, SEM, FT-IR and PL spectroscopy techniques. Monoclinic phase was observed from the XRD and FT-IR studies. SEM image showed agglomeration of nanoparticles. In the emission spectra, band originated from ³P₁–¹S₀ transition of Bi³⁺ ion and bands due to ⁵D₄ → ⁷F_6,5,4,3 transitions of doping Tb³⁺ ion were observed upon excitation at 351 nm. The emission intensity was found to accentuate with the increase in Tb³⁺ ion concentration upto 3at. % and subsequently attenuated with further increase in Tb³⁺ ion concentration due to concentration quenching effect. The decay time of the prepared phosphors was also investigated. The CIE chromaticity diagram revealed a nearly white colour emission upon excited at 351 nm. It is possible that the prepared phosphors may be useful for solid-state lighting.

KEYWORDS:

• BiPO₄:Tb³⁺
• photoluminescence
• concentration effect
• CIE diagram

Acknowledgments

The authors thank the Science and Engineering Research Board (SERB), New Delhi (Vide No. SB/EMEQ-336/2014 dated 04.02.2016) for financial support and NCL Pune for providing SEM facility.

Disclosure statement

No potential conflict of interest was reported by the authors.