氧化银纳米粒子的制备及其动态受激荧光  

Synthesis of Silver Oxide Nano-scale Thin Films and Photo-activated Dynamic Luminescence from Their Nanoparticles

作　　者：张西尧[1] 潘新宇[2] 张琦锋[1] 许北雪[1] 蒋红兵[2] 刘春玲 龚旗煌[2] 吴锦雷[1] 

机构地区：[1]北京大学电子学系,北京100871 [2]北京大学物理学院人工微结构和介观物理国家重点实验室,北京100871

出　　处：《物理化学学报》2003年第3期203-207,共5页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(60071017;19884001;10104003;90101027);国家科技部973(2001CB610503和G1999075209)

摘　　要：采用真空蒸发沉积法和辉光放电氧化法,制备了粒径在5～30nm之间的可控、空间分布均匀、高纯度的氧化银纳米薄膜,使薄膜成岛状生长和避免光照是制备过程中的两个关键问题.用XPS分析了Ag3d和O1s轨道的结合能,计算了银和氧的原子比,证明其成分为Ag2O,用XRD确定了氧化银纳米薄膜最强的衍射峰分别对应Ag2O的(111)、(110)、(200)、(211)晶面族.研究了这种薄膜在可见光波段的光吸收,计算得氧化银的禁带宽度为2.8eV.在蓝光持续照射几分钟激活后,观察到了其中纳米粒子在蓝光激发下发黄光和绿光,在绿光激发下发红光的现象,这种光致发光具有动态“闪烁”的特点.提出了氧化银光分解引入缺陷能级(如Ag3O,Ag+2O和Ag+3O)新的理论模型并对此现象进行定性的解释.Well spatial-dispersed and high purity silver oxide nanoparticles,wh ose size can be controlled from 5 nm to 30 nm,were prepared by vacuum thermal ev aporation and glow discharge oxidation.To form island and keep samples in darkne ss are two key points of synthesis.Based on Ag3d and O1s binding energy and the ratio of silver atoms to oxide atoms given by XPS,the sample was confirmed to be Ag2O.X-ray diffraction of Ag2O nano-scale thin films was acquired and the str ongest diffraction peaks referred to face (111),(110),(200) and (211) of Ag2O.Ab sorption spectra of the samples were also studied.The absorption spectrum indica tes that band gap of silver oxide is 2.8 eV.After being photo-activated by blue light for a few minutes,intermittent green and yellow photoluminescence from si lver oxide nanoparticles were observed with blue excitation.Luminescence from th e same region excited by green light is red and also dynamic.This phenomenon was explained by electron transitions to the impurities energy levels induced by ph otolytic centers(Ag3O,Ag?2O and Ag?3O￡(c)in silver oxide.

关 键 词：氧化银 薄膜 纳米粒子 荧光 

分 类 号：TB383[一般工业技术—材料科学与工程]