del-Castillo J, Yanes A C, Méndez-Ramos J, Rodríguez V D
Departamento Física Básica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain.
J Nanosci Nanotechnol. 2009 Aug;9(8):4834-8. doi: 10.1166/jnn.2009.1371.
Nano-structured glass-ceramics comprising In2O3 nanocrystals (quantum dots) in a silica glassy matrix have been synthesized for the first time to our knowledge, by thermal treatment of sol-gel precursor glasses with different concentrations of In2O3. Undoped and Eu(3+)-doped samples have been obtained and characterized. By means of X-ray Diffraction and Transmission Electron Microscopy analysis, the precipitation of In2O3 cubic crystalline nanoparticles was confirmed. The mean radii of these nanocrystals, from 1 to 4 nm, are comparable to the exciton Bohr radius, corresponding to wide band-gap semiconductor quantum-dots. Under interband UV excitation of the nanocrystals, a broad visible emission is observed in the undoped samples. Meanwhile, the Eu(3+)-doped samples only show emission from these ions which are efficiently excited by energy transfer from the In2O3, nanocrystals. Selective excitation of the Eu3+ ions allow us to discern those remaining in the silica glassy matrix from the ones located in the interface SiO2-In2O3.
据我们所知，首次通过对不同In2O3浓度的溶胶 - 凝胶前驱体玻璃进行热处理，合成了在二氧化硅玻璃基质中包含In2O3纳米晶体（量子点）的纳米结构玻璃陶瓷。已获得未掺杂和Eu(3+)掺杂的样品并对其进行了表征。通过X射线衍射和透射电子显微镜分析，证实了In2O3立方晶体纳米颗粒的沉淀。这些纳米晶体的平均半径为1至4纳米，与激子玻尔半径相当，对应于宽带隙半导体量子点。在纳米晶体的带间紫外激发下，未掺杂样品中观察到宽的可见发射。同时，Eu(3+)掺杂样品仅显示这些离子的发射，这些离子通过从In2O3纳米晶体的能量转移而被有效激发。对Eu3+离子的选择性激发使我们能够区分留在二氧化硅玻璃基质中的离子和位于SiO2 - In2O3界面处的离子。
