Ce和Dy在Cd_(0.5)Zn_(0.5)B_4O_7中的发光特性及能量双向传递

Luminescence Characteristics and Two-way Energy Transfer of Ce and Dy in Cd_(0.5)Zn_(0.5)B_4O_7

采用高温固相法制备了自蓝光双发射为一体的Cd0．5Zn0．5B4O7：Ce／Dy系列发光材料．由XRD测得Cd0.41Zn0．5B4O7：Ce0.04／Dy0．02的晶胞参数：a=1．3885nm，b=0．8020nm，c=0．8670nm，属于正交晶系，Pbca空间群．在Ce／Dy双掺的体系中存在Ce^3＋和Dy^3＋两种发光中心，254～350nm激发主要是Dy^3＋的^4F9/2→^6H15／2和^4F19／2→^6H13／2跃迁发射，而355～390nm激发主要为Ce^3＋的5d→4f跃迁发射．340nm激发Ce／Dy双掺发光体的发射强度是同浓度Dy^3＋单掺的31倍，Ce^3＋是Dy^3＋的高效敏化剂，而355～390nm激发Dy^3＋＋是Ce^3＋的敏化剂．体系中存在少见的Ce^3＋→Dy^3＋与Dy^3＋→Ce^3＋的能量双向传递．

A series of blue-white dual emission luminescent materials, Cd0.5Zn0.5B4O7： Ce/Dy, were prepared via the high temperature solid state method for the first time. Investigating results of XRD show that Cd0. 41Zn0. 5 B4 O7 ： Ce0.04/Dy0.02 belongs to orthorhombic crystal system with Pbca space group and lattice parameters of a = 1. 3885 nm, b =0. 8020 nm, c =0. 8670 nm. There are two kinds of luminescence center, Ce^3＋ and Dy^3＋, in Cd0.5Zn0.5B4O7： Ce/Dy system. Excited by 254--350 nm UV, the emission is mainly due to ^4F9/2→^6H15/2 and ^4F9/2→^6H13/2 of Dy^3＋ , while excited by 355--390 nm UV, the emission is mainly due to 5d→4f of Ce^3＋. Excited by 340 nm UV, the intensity of the phosphor co-doped Ce/Dy is 31 times of the same concentration of Dy single-doped. Ce^3＋ is a high efficient sensitization agent of Dy^3＋. However, when excited by 355--390 nm UV, Dy^3＋ is the sensitization agent of Ce^3＋. A kind of singular two-way transfer of energy phenomenon, Ce^3＋ →Dy^3＋ and Dy^3＋→Ce^3＋ , exists in the system.