A Raman spectroscopy study of the effect of thermal treatment on structural and photoluminescence properties of CVD diamond films

• Published in: Materials & design 2016-12, Vol.112, p.320-327
• Main Authors: Dychalska, Anna, Fabisiak, Kazimierz, Paprocki, Kazimierz, Makowiecki, Jarosław, Iskaliyeva, Aizhan, Szybowicz, Mirosław
• Format: Article
• Language: English
• Subjects: Atomic force microscopy; Chemical vapor deposition; Cooling; CVD diamond films; Diamond films; Diamond structure; Grain boundaries; Hydrogen; Hydrogen concentration; Raman spectroscopy; S parameters; Slopes; Thermal quenching
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2016.09.092

Micro- Raman spectroscopic technique is employed to investigate structural and micro-photoluminescence (μ-PL) properties of diamond films obtained by chemical vapour deposition (CVD) on silicon substrate. Information on the behaviour of PL centred at 2eV upon annealing to 300°C and cooling is obtained from background slope and G band intensity in the Raman spectra (the so-called S parameter). The results show that PL is thermally quenched and this process has a character of continuous of energy distribution due to point defects for temperatures below 100°C. Additionally, the distribution of hydrogen concentration at the diamond films surface of different structures is estimated for room temperature and compared with the results obtained from atomic force microscopy (AFM). The obtained data indicate a correlation between the size and character of the grain boundaries and the hydrogen concentration. [Display omitted] •CVD diamond films exhibit thermal quenching of photoluminescence.•The increase of diamond film thickness leads to increase of Si related activation energy.•Post – growth annealing at 300°C leads to reduction of defects density.•Diamond films with grain size 0.6–0.8µm exhibit more uniform hydrogen distribution compare to grain size 0.5-0.6µm.