锂离子对稀土掺杂氧化物的红外激光诱导热辐射的影响

Effects of Li Ions on the Thermal Radiation Induced by NIR Laser in Rare Earth Doped Oxide

由于具有较高的可见波段荧光效率,基于稀土掺杂氧化物的红外激光诱导热辐射具有重大的应用潜力。进一步提高红外诱导热辐射效率具有重大的实用价值。设计了一种改善稀土掺杂氧化物材料中红外诱导热辐射效率的方案,即通过掺杂改性杂质,既可以改变稀土离子周围局域晶场的对称性;同时又引入了晶格缺陷。对应的效果包括:一方面,可以通过增强稀土离子周围的晶场强度来提高稀土元素对于入射光子的吸收能力;另一方面,可以利用晶格缺陷作为猝灭中心来增加材料的热转化能力,最终将显著提高杂质改性材料的光热转化效率,即获得更加高效的红外诱导热辐射材料。为了验证设计方案的可行性,利用溶胶-凝胶方法合成了不同浓度的镱离子和锂离子的共掺杂样品,通过XRD及TEM测试分析了杂质对样品结构的影响,并且基于荧光发射光谱具体研究了杂质掺杂浓度对热辐射效率的影响。该工作为高效稀土掺杂热辐射材料的制备提供一定的参考。

Thermal radiation induced by NIR laser,from rare earth doped oxides show promising potentials in many applications,due to their relatively high luminescentefficieny in the visible light region.Therefore,further enhancing the efficiency of this type of thermal radiation is of vital importance.In this paper,we proposed a protocol to improve the luminescent efficiency of the thermal radiation,that is,introducing Li+into the oxide hosts,which on one hand could decrease the symmetry around the rare earth ions,and on the other,couldcreate the inner defects due to the mismatch of valences.Beneficial effects of doping Li+including the enhancement of the absorption of rare earth ions atthe incident wavelength(due to the enhanced crystal field),as well as the promotion of producing heat associated with lattice phonons(owing to the increased so called“luminescence quechers”).In addition,we synthesized series ofLi+and Yb 3+doped ZrO 2 using sol-gel technique to experimentally validate our proposed design,influences of doping Li ions on the structure of thennaocrystals were discussed on the basis of XRD and TEM tests;through the emission spectra,the effects of doping concentration were investigated as well.This work may provide references for fabricating oxide phosphors with efficient thermal radiation.