钒酸钇的基质施主合作能量传递导致的镱离子的近红外量子剪裁发光

摘要

The present manuscript researches the near infrared quantum cutting luminescence phenomena of Yb3+ ion in YVO4 crystal matrix.The luminescence spectra,excitation spectra and fluorescence lifetimes were measured.It was found that the ex-citation of YVO4 crystal matrix energy band by 322. 0 nm light can result in the effective secondary cooperative energy transfer of Yb3+ ion from the YVO4 crystal matrix.It results in the intense 985. 5 nm 2F5/2→2F7/2 near infrared quantum cutting lumines-cence of Yb3+ ion.Meanwhile,the 430. 0 nm luminescence intensity of YVO4 crystal matrix decreases greatly.From the experi-mental measurements,it was found that the lifetime of 430. 0 nm fluorescence of (A)Yb(1. 5)∶YVO4 crystal isτA= 3. 785 s and that of (B)YVO4 crystal isτB= 22. 72 s.It was found also that the theoretical efficiency up limit of quantum cutting of (A) Yb(1. 5)∶YVO4 crystal is aboutη1. 5%Yb= 183. 3%.%稀土材料的红外和可见量子剪裁对于寻找更好能量效率的发光材料来说都是一个激动人心的发展。发光效率的最大上限值能从100％提高到200％甚至更高。在第一代晶硅太阳能电池与第二代薄膜太阳能电池之后第三代的聚光太阳能电池已成为目前的重点发展方向。现在，利用稀土材料的近红外量子剪裁发光效应有可能较好的解决太阳光谱与太阳能电池光电响应之间存在的光谱失配的问题，因此有可能较大幅度的提高太阳能电池的发电效率，因而具有重要的意义与价值。研究了钒酸钇晶体基质中Yb3+离子的近红外量子剪裁发光现象，测量了从可见到红外的钒酸钇晶体的发光谱、激发谱与荧光寿命，测量发现钒酸钇晶体基质能带在约322．0 nm 光激发时能导致有效的从钒酸钇晶体基质到Yb3+离子的二级合作能量传递，进而导致了很强的Yb3+离子的985．5 nm 2F5／2→2F7／2的近红外量子剪裁发光，同时，钒酸钇晶体基质的位于430．0 nm的发光强度大幅降低。测量发现：（A）Yb（1．5）∶YVO4晶体的430．0 nm的荧光寿命值为τA＝3．785μs；（B）YVO4晶体的430．0 nm的荧光寿命值为τB＝22．72μs；研究计算发现总的理论量子剪裁效率上限值为η1．5％Yb＝183．3％。