Novel 4ZnO⋅B2O3⋅H2O:Ln3+/HTC (where Ln = Eu or Tb) phosphors: Synthesis, morphology and luminescence properties

Hydrothermal carbon microsphere (HTC) is a carbon-based fluorescent material, which can be synthesized by hydrothermal carbonization of glucose. In this article, a series of 4ZnO·B 2 O 3 ·H 2 O:Ln 3+ /HTC (where Ln = Eu or Tb) composites were prepared under hydrothermal conditions. The effects of the glucose concentration on the morphology, photoluminescence (PL) intensity and emission color of Zn 3.64 :Eu 0.24 [B 2 O 7 ]·H 2 O/HTCx and Zn 3.55 :Tb 0.3 [B 2 O 7 ]·H 2 O/HTC y were investigated. The relationship between morphology and PL intensity of composites was discussed. The results revealed that the presence of HTC did not change the original emission color of 4ZnO·B 2 O 3 ·H 2 O:Ln 3+ (where Ln = Eu or Tb) materials, but greatly increased their PL intensity, the sphere-like morphology composites have the strongest PL intensity. The Zn 3.64 :Eu 0.24 [B 2 O 7 ]·H 2 O/HTCx and Zn 3.55 :Tb 0.3 [B 2 O 7 ]·H 2 O/HTC y emit bright red light and green light, respectively, under respective excitation wavelengths. The present research suggests that the 4ZnO·B 2 O 3 ·H 2 O:Ln 3+ /HTC (where Ln = Eu or Tb) composites may be candidates of red and green phosphors for display and lighting applications.