高温快速退火制备AgNPs/SiO_(2)中保温时间对粒径和形貌的影响  

Effect of Holding Time on Particle Size and Morphology of AgNPs/SiO_(2)Prepared by Rapid Thermal Annealing Method

作　　者：徐艳茹 汪燕青 陈焕明 马骏 侯毅 XU Yanru;WANG Yanqing;CHEN Huanming;MA Jun;HOU Yi(School of Mechanical Engineering,Ningxia University,Yinchuan 750021,China;School of Physics and Electronic-Electrical Engineering,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学机械工程学院,银川750021 [2]宁夏大学物理与电子电气工程学院,银川750021

出　　处：《材料导报》2023年第7期137-141,共5页Materials Reports

基　　金：宁夏自然科学基金(2020AAC03072,2021AAC03059);宁夏回族自治区重点研发计划项目(引才专项)(2021BEB04020)。

摘　　要：高温快速退火法在制备金属纳米结构方面具有成本低廉、几何结构及尺寸可控等优点,被广泛用于等离激元纳米结构的制备。高温退火下纳米颗粒形貌随保温时间的演化机理对纳米结构等离激元效应调控具有重要意义。本工作研究了900℃退火过程中石英基底上纳米银颗粒(AgNPs/SiO_(2))形貌随保温时间的演化。通过热场发射扫描电镜实验和粒径分布统计分析发现,当保温时间为15 s时,连续银膜演变为均匀分散的银岛和二次颗粒,平均粒径分别为(152±46)nm、(53±13)nm。这是由于纳米银颗粒的微观形貌与原始银膜结构缺陷之间存在继承性,高温退火后,原始银膜的沟渠网络通过扩散机制逐渐收缩并分离成条状银岛,而沟渠网络中二次形核的银膜形成较小的纳米银颗粒,即二次颗粒。随着保温时间延长至1 min、5 min,条状银岛逐渐演变为球冠形颗粒,粒径减小,数量几乎不变;10 min时,二次颗粒数量由于熟化蒸发而急剧减少。保温时间为5 min时形成的纳米银作为表面增强拉曼散射基底能够用于10^(-8)mol/L龙胆紫分子的检测。该结果表明通过改变退火时间可以调控纳米银颗粒的形貌和粒径,为快速退火制备等离激元基底提供理论基础,有利于纳米结构在太阳能电池和痕量检测的应用。Rapid thermal annealing is an advantageous method for preparation of plasmonic nanostructures,which offers low cost and controllable size and geometry.The mechanism of nanoparticles evolving with holding time via rapid thermal annealing is significant for turning plasmonic effect of nanostructures.In this work,the morphology evolution of silver nanoparticles on quartz substrate(AgNPs/SiO_(2))under different holding time was studied.The size and geometry of AgNPs were characterized by using the field emission scanning electron microcopy and by using statistical method.It is found that when holding time was 15 s,the continuous silver film transformed into uniform Ag islands and secondary nanoparticles with respective mean size of(152±46)nm and(53±13)nm.This is attributed to that AgNPs inherit the morphology features of original defects produced during silver film sputtering.After annealing,the channel networks in the continuous silver film diffusely shrink to strip islands.The secondary nucleuses originally grew in the channel network turn into small nanoparticles,which are called the secondary nanoparticles.When the holding time increases from 15 s to 1 min and 5 min,the strip islands change into spherical crown particles with size decreased and quantity unchanged.When annealed for 10 min,the number of secondary nanoparticles substantially drops resulting from the evaporation during the ripening process.It is found that AgNPs annealed for 5 min exhibits significant plasmonic effect in the surface enhanced Raman scattering measurement of crystal violet molecules,with content as low as 10^(-8)mol/L.It reveals that the geometry and size of AgNPs can be turned via regulating the holding time,providing a theoretical base for preparation of plasmonic substrate by rapid thermal annealing.It also helps for applications of plasmonic nanostructures into solar cells and trace detection.

关 键 词：表面等离激元(SP) 高温快速退火 离子溅射 纳米银膜 保温时间 形貌演化 

分 类 号：TB34[一般工业技术—材料科学与工程]