Bi2S3纳米晶掺杂钠硼硅玻璃的三阶非线性光学性质

利用溶胶-凝胶方法制备了1 wt%Bi2S3纳米晶掺杂钠硼硅玻璃.利用X射线粉末衍射仪(XRD),X射线光电子能谱(XPS),透射电子显微镜(TEM),X射线能量色散谱(EDX),扫描模式透射电子显微镜(STEM)以及高分辨透射电子显微镜(HRTEM)对Bi2S3纳米晶在钠硼硅玻璃中的形貌和微结构进行了表征,同时,利用飞秒Z扫描技术在波长为770 nm对该玻璃的三阶非线性光学性能进行了分析测试.结果表明,尺寸为10～30 nm的Bi2S3正交晶系纳米晶在钠硼硅玻璃中形成,该玻璃的三阶非线性光学折射率γ、三阶非线性吸收率β和三阶非线性极化率χ(3)分别为5.90×10-16 m2/W、7.35×10-9 m/W和4.55×10-18 m2/V2.其中,该玻璃的三阶非线性极化率值比未经掺杂的钠硼硅玻璃(χ(3)=1.09×10-22 m2/V2)高出4个数量级,这表明,随着Bi2S3纳米晶的引入,该玻璃的三阶非线性光学性能将得到显著的提高.     

Bi2O3纳米晶玻璃三阶非线性光吸收性质的研究

利用溶胶凝胶法结合气氛控制方式合成了含Bi2O3纳米晶钠硼硅玻璃.利用X射线粉末衍射仪(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、X射线能量色散谱(EDX)、扫描模式透射电子显微镜(STEM)、高分辨透射电子显微镜(HRTEM)以及选区电子衍射(SAED)对掺杂在钠硼硅玻璃中Bi2O3纳米晶的形貌和微结构进行了表征,同时,利用飞秒开孔Z-scan技术详细地研究了Bi2O3纳米晶玻璃在800 nm处不同激发光强度下的三阶非线性光吸收性质.结果表明,在钠硼硅玻璃中形成了尺寸小于10 nm的Bi2O3单斜晶系纳米晶.随着激发光强度的增强,该玻璃的三阶非线性光吸收性质产生由饱和吸收向反饱和吸收的转变.进一步,计算得到的该玻璃三阶非线性极化率χ(3)的数量级范围在10-19~10-18m2/V2之间.这一结果说明该玻璃具有良好的非线性光学性能,并且在光限幅器等非线性光学领域具有潜在的应用价值.     

含Ag量子点钠硼硅玻璃的三阶非线性光学性质

以正硅酸乙酯、硼酸、金属钠为前驱体采用溶胶-凝胶法合成含Ag量子点的钠硼硅玻璃。X射线粉末衍射 (XRD) 分析Ag量子点具有立方相。通过透射电子显微镜 (TEM) 和高分辨透射电子显微镜 (HRTEM) 测定量子点的尺寸和分布, 结果显示在玻璃中量子点呈规则的球形, 并且尺寸在5~13 nm之间。紫外-可见(UV-Vis)吸收光谱仪得到Ag量子点的表面等离子体共振吸收峰大约在406 nm附近; 利用飞秒Z-scan 技术在800 nm波长处用飞秒钛宝石激光辐照对Ag量子点玻璃的非线性光学性质进行研究, 该玻璃的非线性折射率γ、非线性吸收系数β和三阶非线性极化率χ⁽³⁾分别为 –1.72×10^-17 m²/W、9.96×10^-11 m/W、1.01×10^-11 esu。     

ZnO含量对熔融法制备PbSe量子点玻璃的影响

采用高温熔融－退火法在钠硼铝硅酸盐（SiO2-B2O3-Na2O-Al2O3-ZnO-AIF3-Na2O）玻璃中生长了PbSe量子点,通过X射线衍射（XRD）、透射电镜（TEM）、光致荧光（PL）谱等研究了玻璃配料中不同ZnO含量对PbSe量子点尺寸和浓度的影响,结果表明,ZnO含量占总玻璃配料质量比约9．4％时,生成的量子点尺寸比较均匀,直径约为6．5nm,且浓度较高,PL谱强度最强,辐射峰位于1790nm,FWHM为296nm。玻璃配料中加入适量的ZnO有助于PbSe量子点的形成,减少Se元素的挥发,使玻璃中的量子点尺寸分布趋于均-化。     

水溶性CdHgTe合金量子点的制备与表征

以巯基乙酸为稳定剂, 在水溶液中加热CdCl₂、HgCl₂ 和 NaHTe的混合物直接合成CdHgTe合金量子点. 分别用荧光光谱、红外光谱、X射线衍射及透射电镜对其光谱性能、表面基团和结构形貌进行了表征. 结果表明, 合金量子点的发射波长在536到688 nm范围内连续可调, 掺杂后量子点的发射光谱变宽, 半高峰宽为70~90 nm; CdHgTe的荧光量子产率介于1.5%到6.7%之间; 巯基与CdHgTe量子点表面的Cd²⁺离子发生键合, 而使巯基乙酸结合于量子点表面; 合金量子点具有闪锌矿结构; 量子点分散性好, 形貌呈颗粒状.     

基于废弃火炬松木包装的碳量子点制备与性能

目的 为了改善废弃火炬松木材包装综合利用率低和功能化利用严重不足的现状,以其包装废弃物制备荧光碳量子点,实现高附加值利用。方法 首先,以废弃火炬松木材包装为碳源,以尿素和磷酸分别为氮、磷掺杂剂,采用水热法(温度为200 ℃、时间为12 h),制备氮磷掺杂碳量子点。接着,采用紫外可见光分光光度计、荧光分光光度计、透射电子显微镜、傅里叶红外光谱和X射线光电子能谱表征CQDs的物理结构、化学结构和光学性质,筛选出荧光强度高、荧光量子产率大的制备工艺。结果 所制备的氮磷掺杂火炬松荧光碳量子点呈规则的球形,其平均粒径为2.25 nm、粒径分布范围为1.3~3.4 nm,且在水溶液中分布均匀,无明显聚集;碳量子点表面具有丰富的醚键、碳碳双键以及含磷和含氮官能团;当火炬松木粉、去离子水、尿素、磷酸的质量比为1∶60∶0.5∶0.5时,所得荧光碳量子点的荧光最强、荧光量子产率最高,所得荧光量子产率比未掺杂碳量子点的提高了5.54倍。结论 以废弃火炬松木材包装为碳源制备荧光碳量子点的策略是可行的,可为火炬松木材包装废弃物的高值化和功能化利用提供了一条新的途径。     

Mn~(2+)掺杂水溶性ZnS量子点的制备及其光致发光性能

采用共沉淀法,在3-巯基丙酸(MPA)为表面修饰剂下,成功制备出Mn2+掺杂水溶性ZnS量子点。利用X射线衍射仪、透射电子显微镜、紫外-可见吸收光谱仪和荧光分光光度计等表征方法研究了Mn2+掺杂剂及掺杂量对ZnS量子点的晶体结构、形貌和发光性能等的影响。结果表明,所得产物为ZnS立方型闪锌矿结构,样品呈不规则球形,粒径主要集中在9.7nm左右;在320nm激发下,Mn2+掺杂ZnS量子点出现两个发射波峰,分别位于587和637nm处,其中587nm处的发射波峰为ZnS表面态缺陷发光,而637nm处的发射波峰则属于Mn2+∶4T1-6A1能级特征发光。同时,利用红外吸收光谱对Mn2+掺杂水溶性ZnS量子点的形成机理进行了初步探讨。     

Co2+掺杂水溶性ZnS量子点的制备及其光致发光性能

采用共沉淀法,以3-巯基丙酸为表面修饰剂,成功制备出Co2+掺杂水溶性ZnS量子点。采用X射线衍射仪、透射电子显微镜、原子发射光谱仪、紫外-可见吸收光谱仪和荧光分光光度计等,研究了Co2+掺杂剂及掺杂量对ZnS量子点的晶体结构、形貌和发光性能等的影响。结果表明:所得产物均为ZnS立方型闪锌矿结构,量子点呈不规则球形,粒径主要集中在5.2 nm左右;掺杂样品发红色荧光,发光性能明显增强,属于Co2+形成的杂质能级(4A1—4T1)与缺陷的复合发光。同时,利用红外吸收光谱对Co2+掺杂水溶性ZnS量子点的形成机理进行了初步探讨。     

无机材料学报第18卷2003年总目次

!第1期」综述纳米zno的研究及其进展....……,..…,..................................……杨秀健,施朝淑,许小亮(l)Zno薄膜p型掺杂的研究进展.............……X射线荧光光谱在晶体材料组成分析中的应用..…二,叶志镇,张银珠,徐伟中,等(n)…卓尚军,陶光仪,吉昂,等(19) 研究论文PbBrZ一PbFZ一P205玻璃的结构研究.....……,.......···...··....·.....……赵宏生,李艳青,周万城,等(27)强光致磷酸盐激光玻璃的色心及其ESR研究.............................……姜雄伟,邱建荣,朱从善,等(34)掺杂CuCI钠硼硅玻璃的溶胶一凝胶方法制…     

K_2CO_3对ZnO纳米晶掺杂锌铝硅玻璃的制备及光学性能的影响

利用高温熔融和后续热处理方法获得了ZnO纳米晶掺杂的SiO2-Al2O3-ZnO-K2CO3(SAZK)玻璃。利用差热分析(DSC)、透射电镜(TEM)、X射线衍射谱(XRD)、傅里叶红外光谱(FT-IR)和荧光光谱(PL)等对样品进行了表征。随着玻璃组分中K2CO3含量逐渐升高,热处理后SAZK玻璃中的主晶相逐渐由Zn2SiO4变为ZnO。在325nm激发下,ZnO纳米晶掺杂的SAZK玻璃在580nm处有一个宽波段发射峰。在K2CO3含量为8%(摩尔分数)时,SAZK玻璃的发射强度最大。     

水溶性ZnS量子点的共沉淀法制备、 表征及其光学性能

以硫化钠和乙酸锌为反应物,3-巯基丙酸为表面包覆剂,利用共沉淀法制备了水溶性ZnS量子点。并采用X射线衍射仪、透射电子显微镜和荧光分光光度计等对样品的结构、形貌、粒径和光学性能进行了表征。结果表明:所得样品为ZnS立方型闪锌矿结构,量子点的形状呈不规则球形,粒径主要集中在4.8nm左右;样品在585～590nm之间出现了黄色荧光发射波峰。同时,利用红外光谱对ZnS量子点的合成机理进行了初步分析。     

One-step and rapid synthesis of composition-tunable and water-soluble ZnCdS quantum dots

ZnCdS quantum dots have been successfully prepared at room temperature in aqueous solution with sodium hexametaphosphate as stabilizer and thioacetamide as the source of S. The photoluminescence (PL) spectra and UV-Vis absorption spectra of the ZnCdS quantum dots were determined on the basis of the initial Cd/Zn mole ratio (Cd/Zn = 8/0, 7/1, 6/2, 5/3, 4/4, 3/5, 2/6, 1/7 and 0/8) and the concentration of thioacetamide. The emission peaks first showed a red shift and then a blue shift with the increasing initial Zn concentration, which provided the evidence of formation of CdS/ZnCdS core/shell and ZnCdS alloyed quantum dots. The ZnCdS quantum dots were compared with CdS (ZnS) quantum dots doped with Zn2+ (Cd2+). The samples have also been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS).     

Luminescence of er doped ZnS quantum dots excited by infrared lasers

ZnS:Er quantum dots were prepared in aqueous medium from readily available precursors. The construction, morphology and luminescence properties of the ZnS:Er quantum dots were evaluated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and photoluminescence spectra. The average particle size was calculated using the Scherrer formula to be 4 nm, which is also observed from high resolution transmission electron microscopy (HRTEM) image. Different laser wavelengths at 976 +/- 2 nm and 1480 nm were utilized as the excitation source. ZnS:Er quantum dots had a fluorescence spectrum in 1550 nm region through the 4I13/2 --> 4I15/2 transition. Furthermore, intensity increased with increasing excitation intensity and dopant concentration. The reason for the photoluminescence spectra broadening is discussed. It is because the energy levels of Er3+ are split by a coulombic interaction between electrons, including spin correction and spin-orbit coupling, and eventually by the Stark effect due to ZnS QDs crystal field and local coordination.     

A one-pot aqueous synthesis of high-luminescent thiol-capped CdTe and its bioapplication

Our study described a synthesis of thiol-capped high-luminescent (quantum yield as high as 80%) CdTe quantum dots (QDs) with a facile method in aqueous phase. The fluorescence of the as-prepared CdTe QDs could be tuned from 500 nm to 650 nm. More importantly, after beta-actin conjugation, the CdTe QDs were successfully conjugated with live cells to observe their configurations, demonstrating their potentially broad application as biolabels. The crystal structure, morphology and optical property of the products were investigated by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and fluorescence spectrophotometer.     

Structural,linear and third-order nonlinear optical properties of Cu nanocrystal in sodium borosilicate glass

Cu nanocrystals embedded in sodium borosilicate glass of varied Cu contents from 0.5 to 1.5 wt% have been successfully prepared through a sol–gel process. According to the results of X-ray diffraction (XRD) and the energy dispersive X-ray spectrometry (EDS), the metal Cu nanocrystals in cubic crystal system were well distributed inside glass matrix. Fourier Transform Infrared (FTIR) indicated the sodium borosilicate matrix had no major structural change for gels with different Cu contents. The optical absorption peaks due to the surface plasmon resonance of Cu particles were observed in the wavelength range of 550–600 nm. The absorption peak showed a red-shift trend with increasing Cu contents from 0.5 to 1.5 wt%. Transmission electron microscopy (TEM) revealed the existence of spherical Cu nanocrystals in the matrix. The diameter of Cu nanocrystals varied from 1 to 3.5 nm. Furthermore, the third-order nonlinear optical properties were investigated by Z-scan technique at 800 nm. Experimental results indicated the Cu nanocrystals have obvious positive refractive nonlinearities and reverse saturated absorption performance.