Controllable synthesis, growth mechanism and luminescence property of a novel monodisperse microsphere with a hole for Zn8[(BO3)3O2(OH)3]:Eu3+

Abstract

A novel monodisperse microsphere with a hole for Zn₈[(BO₃)₃O₂(OH)₃]:Eu³⁺ phosphor was controllably prepared by a hydrothermal method and was characterized by XRD, EDS, FT-IR, TG-DTA, SEM, and HRTEM. The influence of hydrothermal reaction time, temperature and doping concentration on the formation of Zn₈[(BO₃)₃O₂(OH)₃]:Eu³⁺ microstructures was investigated, and an ideal monodisperse microsphere of about 5 μm in diameter was obtained at 150 °C for 12 h with the Eu³⁺ doping concentration of 5%, which was self-assembled by nanoplates of about 150 nm in thickness. The crystal growth mechanism was proposed as a nucleation–dissolution–recrystallization process on the basis of time-dependent experiments. The influence of Eu³⁺ doping concentration and reaction time on the photoluminescence (PL) properties of Zn₈[(BO₃)₃O₂(OH)₃]:Eu³⁺ phosphor and the corresponding Eu³⁺ preferential site occupancy have also been investigated. The results show that the Zn₈[(BO₃)₃O₂(OH)₃]:Eu³⁺ microsphere with a hole product exhibits both higher intensity and the highest R/O ratio under 245 nm excitation, so it can be used as a potential red luminescent material.