ZnS：Cu, Eu nanocrystals with an average diameter of 80 nm are synthesized using a hydrothermal approach at 200 ℃. The photoluminescence （PL） properties of the ZnS：Cu, Eu nanocrystals before and after annealing, ...ZnS：Cu, Eu nanocrystals with an average diameter of 80 nm are synthesized using a hydrothermal approach at 200 ℃. The photoluminescence （PL） properties of the ZnS：Cu, Eu nanocrystals before and after annealing, as well as the doping form of Eu, are studied. The as-synthesized samples are characterized by X-ray diffraction, scanning electron microscopy, inductively coupled plasma-atomic emission spectrometry, and the excitation and emission spectra （PL）. The results show that both Cu and Eu are indeed incorporated into the ZnS matrix. Compared with the PL spectrum of the Cu mono-doped sample, the PL emission intensity of the Cu and Eu-codoped sample increases and a peak appears at 516 nm, indicating that Eu3＋ ions, which act as an impurity compensator and activator, are incorporated into the ZnS matrix, forming a donor level. Compared with the unannealed sample, the annealed one has an increased PL emission intensity and the peak position has a blue shift of 56 nm from 516 nm to 460 nm, which means that Eu3＋ ions reduce to Eu2＋ ions, thereby leading to the appearance of Eu2＋ characteristic emission and generating effective host-to-Eu2＋ energy transfer. The results indicate the potential applications of ZnS：Cu, Eu nanoparticles in optoelectronic devices.展开更多
Copper-doped ZnS （ZnS：Cu） nanocrystals are synthesized by the sol-gel method. The average size of the ZnS：Cu nanocrystals is 3.1 nm. The x-ray diffraction indicates that increasing the Cu-dopant concentration resu...Copper-doped ZnS （ZnS：Cu） nanocrystals are synthesized by the sol-gel method. The average size of the ZnS：Cu nanocrystals is 3.1 nm. The x-ray diffraction indicates that increasing the Cu-dopant concentration results in a large shift in the diffraction angle. The effects of the dopant concentration, the reactant ratio, and aging temperature on the optical properties of the ZnS：Cu nanocrystals are also investigated. The fluorescence emission mechanism is analyzed by peak deconvolution using Gaussian functions. We find that the emission of the ZnS：Cu nanocrystal is composed of different luminescence centers at 430, 470, 490, 526, and 560 nm. The origins of these emissions are discussed and demonstrated by controlled experiments.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.10374011)the Doctoral Fund of Dalian Nationalities University,China(Grant No.20116201)
文摘ZnS：Cu, Eu nanocrystals with an average diameter of 80 nm are synthesized using a hydrothermal approach at 200 ℃. The photoluminescence （PL） properties of the ZnS：Cu, Eu nanocrystals before and after annealing, as well as the doping form of Eu, are studied. The as-synthesized samples are characterized by X-ray diffraction, scanning electron microscopy, inductively coupled plasma-atomic emission spectrometry, and the excitation and emission spectra （PL）. The results show that both Cu and Eu are indeed incorporated into the ZnS matrix. Compared with the PL spectrum of the Cu mono-doped sample, the PL emission intensity of the Cu and Eu-codoped sample increases and a peak appears at 516 nm, indicating that Eu3＋ ions, which act as an impurity compensator and activator, are incorporated into the ZnS matrix, forming a donor level. Compared with the unannealed sample, the annealed one has an increased PL emission intensity and the peak position has a blue shift of 56 nm from 516 nm to 460 nm, which means that Eu3＋ ions reduce to Eu2＋ ions, thereby leading to the appearance of Eu2＋ characteristic emission and generating effective host-to-Eu2＋ energy transfer. The results indicate the potential applications of ZnS：Cu, Eu nanoparticles in optoelectronic devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61205193,61204065,and 61307045)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20112216120005)the Developing Project of Science and Technology of Jilin Province,China(Grant Nos.201201116,20140520107JH,and 20140204025GX)
文摘Copper-doped ZnS （ZnS：Cu） nanocrystals are synthesized by the sol-gel method. The average size of the ZnS：Cu nanocrystals is 3.1 nm. The x-ray diffraction indicates that increasing the Cu-dopant concentration results in a large shift in the diffraction angle. The effects of the dopant concentration, the reactant ratio, and aging temperature on the optical properties of the ZnS：Cu nanocrystals are also investigated. The fluorescence emission mechanism is analyzed by peak deconvolution using Gaussian functions. We find that the emission of the ZnS：Cu nanocrystal is composed of different luminescence centers at 430, 470, 490, 526, and 560 nm. The origins of these emissions are discussed and demonstrated by controlled experiments.
