Tunable multicolor and white luminescence in Tb3+/Dy3+/Mn2+ doped CePO4 via energy transfer

Abstract

In this paper, a series of Tb3+/Dy3+/Mn2+ doped CePO4 downconversion nanophosphors (DCNPs) were prepared by a one-pot hydrothermal process. The obtained DCNPs presented monoclinic and hexagonal phase structure with wire-like shape. The photoluminescence (PL) properties and the energy transfer (ET) mechanism of these DCNPs were investigated in detail. The ET mechanism of Ce3+/Tb3+ in CePO4 host was calculated by means of concentration quenching and spectral overlapping, and calculation results revealed that dipole–dipole interactions should be more responsible. The maximum value of ET efficiency was measured to 87.4% for Tb3+ doped CePO4 system. In addition, owing to the efficient ET between Ce3+ and Tb3+/Dy3+/Mn2+, these as-prepared DCNPs exhibit tunable multi-color output under ultra-violet (UV) light excitation. More importantly, the intense cold and warm white emissions can be realized by singly doping 2%Dy3+ and 20%Mn2+ in CePO4 host under UV irradiation, respectively. The corresponding CIE 1931 coordinates were calculated to be (0.30, 0.30) and (0.30, 0.32), respectively, which are closed to the standard white emission (0.33, 0.33). These findings demonstrate the efficient white light emission by singly doped Dy3+ or Mn2+ in CePO4 system for the first time, which is different from commonly used co-doped or tri-doped system. The multicolor tuning and white emission make these Tb3+/Dy3+/Mn2+ doped CePO4 DCNPs potential phosphors in the fields of displays, lighting, and field-emission devices.