Luminescence properties of CaLaB7O13: Eu3+ red-emitting phosphors for near UV-based white LED

A novel red-emtting phosphor CaLa1-xB7O13: xEu3+ (x = 0-0.75) in pure phase were prepared via high temperature solid-state reaction. The crystal structure, luminescent properties, the Commission International de L'Eclairage (CIE) chromaticity coordinates, and thermal stabilities were initially investigated for the application of those phosphors in white light-emitting diode (LED.) Those spectra illustrated that the Eu3+-doped CaLaB7O13 phosphors could efficiently excited by near-UV LED chips and emit several red bands originated from the 5D0→7FJ (J = 1, 2, 3 and 4) transitions of Eu3+ ions. It was demonstrated that electric dipole-quadrupole interaction dominated the energy transfer mechanism in Eu3+-doped CaLaB7O13 phosphors, and the critical distance of energy transfer was estimated to be about 0.563 nm by concentration quenching methods. The CIE color coordinate of the 35.0 at.% Eu3+-doped CaLaB7O13 is (0.611, 0.388), and the temperature-dependent luminescence indicated Eu3+-doped CaLaB7O13 phosphor exhibits mild thermal quenching of fluorescence. Those overall works implied that Eu3+-doped CaLaB7O13 is a promising novel red-emitting phosphor excited by near-UV LED chips and might be potentially applied in white LED.