摘要
制备了单个颗粒(domain)组成的纳米金刚石薄膜,薄膜中单个颗粒由尺寸超过 100 nm 的金刚石晶粒与非晶碳复合而成.对薄膜进行氧化处理后,其硅空位色心的光致发光强度增强了 22.7 倍.扫描电镜及拉曼光谱测试结果表明,不同时间氧化后的样品中存在由尺寸超过 100 nm 的晶粒组成的花瓣状金刚石聚集体,这些金刚石在较长氧化时间下仍能保持稳定.氧化后的薄膜内非晶碳大大减少,金刚石含量增大,纳米金刚石晶粒充分暴露引起了薄膜发光强度大幅增强,其发光半峰宽为 5.6 6.0 nm.继续增加氧化时间,薄膜的光致发光会因为部分细小纳米金刚石晶粒的损失而略微降低,但是稳定的大尺寸金刚石晶粒的存在使得薄膜的发光强度依然维持在氧化前的 8.3 倍以上.
In order to increase the oxidation sites for enhancing the Si-V photoluminescence intensity of nanocrytalline diamond films, we prepare nanocrystalline diamond films;these films each are comprised of separated domains and oxidized for different times. Each single domain consists of nanodiamond grains with a size of larger than 100 nm and amorphous carbon. In the gaps between domains of separated domain there is formed a film that allows more sites to contact air to ensure the efficient oxidation of the film. As a result, silicon vacancy photoluminescence intensity of the separated domain forming the film is largely enhanced by about 22.7 times after oxidation. The SEM images and Raman spectra of oxidized samples show that the film contains flowershaped diamond aggregates, each of which is comprised of radially arranged diamond grains. The mixture of nanodiamond grains and amorphous carbon fills the gaps between diamond petals. These fillers disappear after long-term oxidation, but the diamond petals stay stable. Raman spectra show that the amount of amorphous carbon largely decreases after oxidation, while diamond content apparently rises. Hydrogen is desorbed from the film after short-time oxidation according to Raman spectra, thus the quenching effect on silicon vacancy photoluminescence caused by hydrogen termination of diamond surface state is removed. Diamond petals of large size and nanodiamond grains in the fillers are both silicon vacancy photoluminescence sources of the film;the exposed diamond flats on the surface of unoxidized domains provide limited silicon vacancy photoluminescence for the film. The sufficient exposure of diamond grains after the removal of amorphous carbon leads to the significant enhancement of film’ s silicon vacancy photoluminescence. With longer-time oxidation, the photoluminescence of film will slightly decrease due to the disappearance of small-sized nanodiamond grains, but the film photoluminescence almost remains stable in both intensity and property due to the stability o
作者
陈隆
陈成克
李晓
胡晓君
Chen Long;Chen Cheng-Ke;Li Xiao;Hu Xiao-Jun(College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第16期335-343,共9页
Acta Physica Sinica
基金
国家自然科学基金(批准号:11504325,50972129,50602039)、国家自然科学基金联合重点项目(批准号:U1809210)
国家国际科技合作项目(批准号:2014DFR51160)
国家重点研发计划中欧国际合作项目(批准号:2016YFE0133200)
浙江省重点研发计划国际科技合作“一带一路”专项(批准号:2018C04021)
浙江省自然科学基金(批准号:LQ15A040004,LY18E020013)资助的课题~~
关键词
金刚石
硅空位色心
氧化
光致发光
diamond
silicon vacancy center
oxidation
photoluminescence
