Influences of grain size and microstructure on optical properties of microcrystalline diamond films  

作　　者：Jia-Le Wang Cheng-Ke Chen Xiao Li Mei-Yan Jiang Xiao-Jun Hu 王家乐;陈成克;李晓;蒋梅燕;胡晓君(College of Materials Science and Engineering,Zhejiang University of Technology)

机构地区：[1]College of Materials Science and Engineering,Zhejiang University of Technology,Hangzhou 310014,China

出　　处：《Chinese Physics B》2020年第1期469-474,共6页中国物理B（英文版）

基　　金：Project supported by the Key Project of the National Natural Science Foundation of China(Grant No.U1809210);the National Natural Science Foundation of China(Grant Nos.50972129 and 50602039);the International Science Technology Cooperation Program of China(Grant No.2014DFR51160);the National Key Research and Development Program of China(Grant No.2016YFE0133200);the European Union’s Horizon 2020 Research and Innovation Staff Exchange(RISE)Scheme(Grant No.734578);the Belt and Road International Cooperation Project from Key Research and Development Program of Zhejiang Province,China(Grant No.2018C04021);the Natural Science Foundation of Zhejiang Province,China(Grant Nos.LQ15A040004 and LY18E020013)

摘　　要：Microcrystalline diamond(MCD)films with different grain sizes ranging from 160 nm to 2200 nm are prepared by using a hot filament chemical vapor deposition(HFCVD)system,and the influences of grain size and structural features on optical properties are investigated.The results show that the film with grain size in a range of 160 nm–310 nm exhibits a higher refractive index in a range of(2.77–2.92).With grain size increasing to 620±300 nm,the refractive index shows a value between 2.39 and 2.47,approaching to that of natural diamond(2.37–2.55),and a lower extinction coefficient value between 0.08 and 0.77.When the grain size increases to 2200 nm,the value of refractive index increases to a value between 2.66 and 2.81,and the extinction coefficient increases to a value in a range of 0.22–1.28.Visible Raman spectroscopy measurements show that all samples have distinct diamond peaks located in a range of 1331 cm-1–1333 cm-1,the content of diamond phase increases gradually as grain size increases,and the amount of trans-polyacetylene(TPA)content decreases.Meanwhile,the sp2 carbon clusters content and its full-width-at-half-maximum(FWHM)value are significantly reduced in MCD film with a grain size of 620 nm,which is beneficial to the improvement of the optical properties of the films.Microcrystalline diamond（MCD） films with different grain sizes ranging from 160 nm to 2200 nm are prepared by using a hot filament chemical vapor deposition（HFCVD） system, and the influences of grain size and structural features on optical properties are investigated. The results show that the film with grain size in a range of 160 nm–310 nm exhibits a higher refractive index in a range of（2.77–2.92）. With grain size increasing to 620±300 nm, the refractive index shows a value between 2.39 and 2.47, approaching to that of natural diamond（2.37–2.55）, and a lower extinction coefficient value between 0.08 and 0.77. When the grain size increases to 2200 nm, the value of refractive index increases to a value between 2.66 and 2.81, and the extinction coefficient increases to a value in a range of 0.22–1.28. Visible Raman spectroscopy measurements show that all samples have distinct diamond peaks located in a range of 1331 cm-1–1333 cm-1,the content of diamond phase increases gradually as grain size increases, and the amount of trans-polyacetylene（TPA）content decreases. Meanwhile, the sp2 carbon clusters content and its full-width-at-half-maximum（FWHM） value are significantly reduced in MCD film with a grain size of 620 nm, which is beneficial to the improvement of the optical properties of the films.

关 键 词：microcrystalline diamond films grain size MICROSTRUCTURE optical properties 

分 类 号：TB383.2[一般工业技术—材料科学与工程]