Synthesis and Optical Properties of Ce-doped ZnO

ZnO nanorods were synthesized using the sol-gel method, and the effects of annealing temperature and Ce doping on the morphologies and optical properties of ZnO nanostructures were investigated in detail. The XRD measurements showed that the as-synthesized ZnO nanostructures had a hexagonal wurtzite structure. SEM images showed that uniform nanorods formed at 900 °C. Photoluminescence measurements showed an ultraviolet emission peak and a relatively broad visible light emission peak for the samples sintered at different temperatures. The UV emission peak bathochromically shifted when the annealing temperature rose from 850 to 1000 °C. Ce doping decreased the synthesized temperature of the ZnO nanorods to 500 °C, and the UV peaks hypsochromically shifted.

Synthesis and Photoluminescence of Eu-doped ZnO Nanosheets

Eu-doped ZnO nanosheets were synthesized successfully by means of the hydrothermal method. The X-ray diffraction（XRD） pattern shows that the sample is a single phase with the ZnO-like wurtzite structure. And the X-ray photoelectron spectrum suggests that there are Eu3＋ ions in the matrix of the sample. Eu3＋-related red emissions resulted from energy transfer were observed for the nanosheets under UV laser excitation. The UV, green and yellow emissions were also seen in the photoluminescence spectra.

Synthesis and Soft Magnetic Properties of Mg-doped Ni Nanoparticles

Mg-doped Ni nanoparticles with good soft magnetic properties were prepared with the sol-gel method and were sintered at 400, 500, 600, and 900℃ in argon atmosphere, respectively. The structure and magnetic properties of the samples were studied by means of X-ray diffraction, TEM, and VSM magnetometers. X-Ray powder diffraction results show that Ni-Mg solid solution was formed with the single phase of face-centered cubic（fcc） structure. The particle size became larger with the increase of temperature. When the sintering temperature was 400 °C, the particle size was 6.3 nm, whereas it was 46.2 nm at 900 °C. Both the saturation magnetization（Ms） and the coercivity were enhanced with the increase of the particle size. The Ms values of the samples ranged from 18.965 to 46.766 emu/g and the coercivity ranged from 1051.3568 to 9145.0848 A/m.

Preparation and Luminescence Behavior of CaSiO_3∶Eu^(3+)(Bi^(3+))

CaSiO3：Eu0.08^3＋Bi0.002^3＋ with a monoclinic perovskite structure was synthesized by using sol-gel method, and its luminescence characteristics were investigated. From the excitation spectrum, it can be seen that the main peaks located at 238,396,415,437 and 359 nm correspond to the charge-transfer band of Eu^3＋-O^2- , the absorption transitions of ^7F0.1→^3L6, ^7F0→^5D3, ^7F1→^5D3 of Eu^3＋ ions, and ^3P1→^1S0 of Bi^3＋ ions, respectively. When the samples were excited with a light of wavelength 359 or 395 nm, it can be seen from the emission spectrum that the electronic dipole transition located at 609 nm corresponding to ^5D0→^7F2 of Eu^3＋ ions was stronger than the magnetic dipole transition located at 587 nm corresponding to ^5D0→^7F1 of Eu^3＋ ions, which shows that more Eu^3＋ ions were located in nonreversion center lattices. The energy transfer from Bi^3＋ ions to Eu^3＋ ions in the phosphor was also discussed. The results show that Eu^3＋ ions could be well sensitized by ^3＋ions, and the energy-transfer pattern between Bi^3＋ ions and Eu^3＋ ions was resonance energy transfer.

Structures and Properties of Zn_(1-x)Cu_xO Nanoparticles by Sol-gel Method

Copper-doped ZnO nanoparticles were synthesized by the sol-gel method.The X-ray diffraction（XRD） result shows that Zn1-xCuxO（x≤0.04） samples are single phase with ZnO-like wurtzite structure,while the secondary phase Cu is observed in a Zn0.95Cu0.05O sample.Magnetic measurements indicate that Zn1-xCuxO（x≤0.04） samples are ferromagnetic at room temperature.A strong green peak（520 nm） was observed except for UV band peak in photoluminescent（PL） spectrum of Zn0.98Cu0.02O.

多孔Pb基前驱体的构建对钙钛矿薄膜质量及光伏性能的影响研究

钙钛矿薄膜较大的晶粒尺寸、均匀的表面形貌以及较少的缺陷态是获得高效钙钛矿太阳电池的关键因素.采用PCBM修饰致密TiO_2电子传输层(ETL)表面,利用PCBM自身柔韧性促进形成疏松、多孔的Pb基前驱体薄膜,该结构有利于后续MAI溶液的充分渗透并为前驱体反应形成钙钛矿所必经的应力释放和晶体膨胀过程提供充分空间,从而获得高质量的大晶粒钙钛矿光吸收层.另外,将PbCl_2引入Pb基前驱体中可优化得到多孔骨架结构的PbICl前驱体薄膜,且钙钛矿薄膜中存在的非晶态PbCl_2可有效钝化材料缺陷,显著提高薄膜电学特性及整个电池性能.

双离子电池的研究与应用

锂离子电池(LIBs)是目前人类必不可缺的储能设备之一,可应用于手机、电脑、数码相机、电动汽车以及智能电网等方面.但由于锂资源的有限及其在地壳中分布不均等问题,导致了锂离子电池的制造成本逐渐增加,因此开发低成本、安全、高性能的新型储能器件迫在眉睫.双离子电池(DIBs)因其具有低成本、高能量密度、环保等优点成为人们的研究热点.本文将从双离子电池机理和结构设计进行分析,阐述双离子电池的应用以及双离子电池目前所存在的问题.

CoO@ Ni-Co-S无粘结剂电极材料非对称型超级电容器性能研究

采用水热法和电化学沉积法在泡沫镍上制备了CoO@ Ni-Co-S电极材料,并对其进行了SEM、XRD、XPS表征和电化学性能测试.结果表明:本材料具有较高的电化学性能,在电流密度为1 A/g时,比电容为1 352 F/g;电流密度为10 A/g时,比电容仍能达到1 055 F/g;进一步通过稳定性测试研究发现,在电流密度为2 A/g下充放电2 000次,电容保留率为87%.以CoO@ Ni-Co-S复合材料作为正极,活性炭作为负极构筑非对称型超级电容器,该装置在电流密度为1 A/g时,比电容为209 F/g,操作电压窗口为1. 7 V,功率密度为2. 99 k W/kg时,能量密度可达39. 7 Wh/kg.