CAJ | 학술논문

采用水热法成功的制得了不同形貌的CaMoO4:Eu3+微纳米荧光体.实验结果表明,溶液的pH值在控制产物形貌上起了决定性的作用.用X射线粉末衍射(XRD)、场发射扫描电镜(FE-SEM)和荧光光谱(PL)等分析手段研究了荧光体的结构和光致发光性能.结果表明,CaMoO4:Eu3+荧光体的激发光谱由两部分组成:1个宽的激发带(240～360nm)和属于Eu3+的f-f跃迁的锐线谱(395nm、465nm),它的发射光谱只出现常见的2个发射峰:592nm(5D0→7F1)、615nm(5D0→7F2),其中5D0→7F2跃迁发射峰强度明显高于5D0→7F1跃迁发射峰强度,这表明Eu3+在CaMoO4基质中处于无反演中心或偏离反演中心的格位上.本文还对造成发射峰强度变化的原因进行了分析,认为影响发射峰强度的原因有两个:表而积和对称性,材料的表面积越大,发光的猝灭越严重,荧光发射越弱;材料的结构对称性越差,跃迁戒律打破地越彻底,荧光发射越强.
채용수열법성공적제득료불동형모적CaMoO4:Eu3+미납미형광체.실험결과표명,용액적pH치재공제산물형모상기료결정성적작용.용X사선분말연사(XRD)、장발사소묘전경(FE-SEM)화형광광보(PL)등분석수단연구료형광체적결구화광치발광성능.결과표명,CaMoO4:Eu3+형광체적격발광보유량부분조성:1개관적격발대(240～360nm)화속우Eu3+적f-f약천적예선보(395nm、465nm),타적발사광보지출현상견적2개발사봉:592nm(5D0→7F1)、615nm(5D0→7F2),기중5D0→7F2약천발사봉강도명현고우5D0→7F1약천발사봉강도,저표명Eu3+재CaMoO4기질중처우무반연중심혹편리반연중심적격위상.본문환대조성발사봉강도변화적원인진행료분석,인위영향발사봉강도적원인유량개:표이적화대칭성,재료적표면적월대,발광적졸멸월엄중,형광발사월약;재료적결구대칭성월차,약천계률타파지월철저,형광발사월강.
Eu3+doped CaMoO4 micro/nanophosphors with various shapes have been synthesized by the hydrothermal method. Results showed that the pH value of the precursor solution played a key role in the formation of products with different morphologies. CaMoO4:Eu3+ nanorods, microcubes, microoctahedrons were obtained and characterized by the X-ray powder i diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) and photoluminescence spectrophotometer (PL). The excitation spectra showed a broad intense band (240nm-360hm) and a number of small peaks centered at wavelengths extending from 360 nm to 500 nm corresponding to the inner 4f-shell excitations of Eu3+(395nm、465nm). The emission spectras showed the two common emission peaks: 592nm (5D0→7F1) and 615nm (5D0→7F2). Obviously, the intensity of 5D0→7F2 is stronger than that of 5D0→7F1, which indicate that the Eu3+ ion locates in a noneentrosymmetric position, or occupies the sites derived from an inversion center in this compound. The reasons of different morphologies with different intensity were also investigated. It is generally assumed that change of the intensity of CaMoO4:Eu3+ is mainly attributed to the surface area and environment effects of materials, as the surface area enlarge, the intensity decreased due to the higher quenching; the probability of the forbidden transition increased as the symmetry of micro-structure decreased.