【摘要】 BaGd2ZnO5∶Yb3+,Er3+是目前报道的上转换效率最高的发光材料,有广泛的应用前景,但到目前为止还没有关于该基质材料中Er3+发光动力学过程研究的报道。采用溶胶凝胶法制备BaGd2ZnO5∶Yb3+,Er3+上转换发光材料,测量不同激发密度下上转换光发射功率及上转换效率。数据表明:当激发密度较低时,绿色光发射强度与激发光功率的二次方成正比;激发密度较高时,与激发光功率的一次方成正比;上转换能量效率先增大后减小,具有一个极大值。通过建立不同激发密度下,Er3+离子4 S3/2能级上转换光发射速率方程模型,阐述了产生这一现象的动力学过程和绿色光发射产生的机理。在弱激发条件下,用方波调制的971nm LD激光激发BaGd2ZnO5∶Yb3+,Er3+样品,测量上转换绿光的上升和衰减过程,用Er3+离子4 S3/2能级的速率方程拟合绿光的上升和衰减过程确定相关参数,证实Er3+离子4 S3/2能级粒子布居主要来自于Yb3+→Er3+的能量传递。更多还原

【Abstract】 Yb3+/Er3+ co-doped BaGd2ZnO5 phosphors were prepared by using the sol-gel method.The up-conversion luminescence powers and efficiencies were measured under different excitation densities.The obtained data showed that the green luminescence power was proportional to the second-order of that of the excitation power under the lower excitation density and linearly in the higher one.The up-conversion mechanism under different excitation power was described by a rate equation.Yb3+/Er3+ co-doped BaGd2ZnO5 was excited by 971 nm LD laser with a square wave signal modulation and the rise and decay processes of green up-conversion luminescence were measured.In a low excitation condition,the rate equation of the energy level 4S3/2 for Er3+ ions was used to fit the green rise and decay processes in order to fix the relevant parameters,and confirm that the population of 4S3/2 energy level of Er3+ ion mainly came from the energy transfer from Yb3+ to Er3+.更多还原