부산대학교 도서관

A layer-by-layer growth method, namedherein as impregnation–decompositioncycles (IDCs), was used to build hierarchically nanostructured multilayerednanoparticles, alternating undoped ZnO and Eu(III)-doped ZnO layersin order to thermally induce Eu(III) migration into the ZnO structure.Porous Vycor glass (PVG) was used as a mesoporous silica host, wherethe pores were used as a confined environment for preparation of ZnOnanoparticles. The proposed method allowed the control over the growthand size of the nanoparticles and prevented their coalescence. HRTEMimages and XRD data revealed that ZnO nanoparticles are spheroidalwith a wurtzite crystal structure and an average diameter of 4.8 nmfor 10 IDCs. UV–vis DRS data indicated that the formation ofZnO nanoparticles is favored by europium(III) doping, indicated bythe band-gap absorption detection that also undergoes a red-shiftby increasing the IDC number. Photoluminescence emission spectra haveshown Eu(III) intraconfigurational 4f–4f and ZnO excitonicemissions. Excitation spectra have shown energy transfers from ZnOto the silica as well as an energy transfer from ZnO to Eu(III) ions,indicating the migration of these ions into the ZnO structure. [ABSTRACT FROM AUTHOR]