兰州大学机构库 >物理科学与技术学院
基于介孔氧化硅的发光材料的制备、结构与性能
Alternative TitlePreparation, structure, and properties of luminescence materials based on mesoporous silica
陆青山
Thesis Advisor李建功
2010-05-30
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name博士
Keyword介孔材料 硅酸锌 硅酸钇 氧化锌 Eu3+ Mn2+ 发光
Abstract利用两溶剂法在介孔材料SBA-15中组装ZnO团簇,得到ZnO/SBA-15纳米复合材料。ZnO含量高的ZnO/SBA-15纳米复合材料保持有序的二维六方介孔结构。ZnO以非晶态或团簇的形式稳定存在于SBA-15的孔道中。由于受SBA-15孔道限域空间作用,ZnO表现出量子尺寸效应,禁带宽度变宽,近带边发射向短波长方向移动,发生了显著的蓝移。 以萃取介孔材料SBA-15为硅源,在800°C下煅烧2 h得到锰掺杂硅酸锌(Zn2SiO4:Mn2+)发光材料,该煅烧温度明显低于传统固相反应的煅烧温度,同时也低于以退火SBA-15为硅源时的煅烧温度。紫外光245 nm激发下,发光中心Mn2+直接被激发;在真空紫外147 nm激发下,激发能量被基质晶格吸收并通过交换作用传递到发光中心Mn2+,伴随着Mn2+从激发态跃迁到基态,产生527 nm的绿光发射。 采用介孔氧化硅SBA-15模板路线,以SBA-15作为无机硅源,通过高温固相反应在1300oC下制备出铕掺杂的硅酸钇(Y2SiO5:Eu3+)发光材料。Y2SiO5:Eu3+结晶性好、颗粒致密、表面光滑、颗粒大小在微米尺度。发射光谱显示了Eu3+的特征发射,且Eu3+占据对称性低的格位。 以三嵌段共聚物F127为结构导向剂,通过溶胶凝胶和蒸发诱导自组装技术,利用旋涂法在不同基底上制备出Eu3+掺杂立方介孔氧化硅薄膜材料。介孔薄膜的介观结构具有体心立方对称性,薄膜连续、光滑、没有微裂纹,厚度大约为205 nm。当Eu3+的掺杂量达到5.24%(Eu/Si),煅烧温度为600°C,薄膜仍然保持高度有序性。激发光谱显示出波长位于246 nm处的Eu3+-O2-电荷迁移带,说明掺杂在薄膜中的Eu3+与O2-形成键合。发射光谱中观察到Eu3+的两个特征发射峰。
Other AbstractIn this work, the luminescence materials based on mesoporous silica were prepared, and their structures and photoluminescence properties were studied. The studies are as follows. The two-solvent method was employed to prepare ZnO clusters encapsulated in mesoporous silica SBA-15 (ZnO/SBA-15). The ZnO/SBA-15 nanocomposite has the ordered hexagonal mesostructure. ZnO clusters are distributed in the pores of SBA-15. The photoluminescence spectra show the emission band centered at about 370 nm which can be fitted by three emission Gaussian peaks: the UV emission band around 367 nm, the violet emission around 420 nm, and the blue emission around 457 nm. The UV emission is attributed to near band-edge emission of ZnO. The violet emission results from the oxygen vacancies on the ZnO-SiO2 interface traps. The blue emission is from the oxygen vacancies or interstitial zinc ions of ZnO. The UV emission shows a significant blue shift due to quantum size effect compared to the emission of the bulk counterpart reported. The ZnO clusters encapsulated in SBA-15 can be used as ultra-violet light-emitting material. Mn2+ ions-doped Zn2SiO4 (Zn2SiO4:Mn2+) powders were prepared by solid-state reaction using extracted SBA-15 as silica source. The well crystalline willemite Zn2SiO4:Mn2+ can be obtained at 800°C which is much lower than the conventional solid state reaction temperature and lower than using the calcined SBA-15. The reason is that the extracted SBA-15 provides large surface area, high density silanol groups, and large pore size, which may increase the reaction interfaces, enhance the reaction kinetics, and decrease the reaction temperature. Ultraviolet (UV) and vacuum ultraviolet (VUV) excitation spectra reveal the host lattice absorption band around 162 nm and the charge transfer transition band around 245 nm. The Zn2SiO4:Mn2+ phosphor exhibits a strong green emission around 527 nm. The Zn2SiO4:Mn2+ phosphor with the Mn2+ doping concentration of 0.06, i. e., Zn1.94Mn0.06SiO4, shows the highest relative emission intensity. Upon 147 nm excitation, the luminescence decay time of the green emission of Zn1.94Mn0.06SiO4 around 527 nm is 8.87 ms, which is consistent with the value of 8-16 ms as reported. Eu3+ ions-doped Y2SiO5 (Y2SiO5:Eu3+) samples were prepared by solid-state reaction at a calcination temperature of 1300°C using SBA-15 as silica source without fluxes. The results show that the crystalline Y2SiO5:Eu3+ particles are dense, weak agglomeration, and h...
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Language中文
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/229796
Collection物理科学与技术学院
Recommended Citation
GB/T 7714
陆青山. 基于介孔氧化硅的发光材料的制备、结构与性能[D]. 兰州. 兰州大学,2010.
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