Anomalous Green Luminescent Properties in CVD Synthetic Diamonds

Amber M Wassell,Peter M P Lanigan,Chris Hodges,David Fisher,Stephen A Lynch,Philip M Martineau,Colin D Mcguinness,Mark E Newton

doi:10.1002/pssa.201800292

Amber M Wassell, Peter M P Lanigan + Show 6 more

Open Access

https://doi.org/10.1002/pssa.201800292

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Abstract

In this paper, the authors explore the spectral properties of a sharp emission line centered at 499.6 nm (reported previously as 499 nm) observed in the UV‐luminescence spectrum of synthetic CVD diamond gemstones. These gemstones also exhibit spectrally prompt broad blue luminescence centered at 435 nm which is similar in character to the 425 nm blue luminescence characteristic of type IIa natural diamonds. By comparing the results against synthetic CVD diamond material which has been subjected to high temperature anneals, the authors can speculate on the nature of the defect associated with this color center. Since the 499 nm spectral line has only been observed in synthetic CVD diamonds to date, the authors further propose that it can be helpful in the identification of synthetic diamonds, in particular those showing the blue luminescence signature usually associated with type IIa natural diamonds.

Highlights

Introduction reproducibleCertain optical signatures will raise concerns because they indicate the presence ofThe unique combination of diamond’s optical and mechanical additional elements, or point and extended defects, not properties mean that it is prized above all other materials as a commonly found in natural diamonds
We have investigated the properties of a sharp spectral feature centered at 499 nm in chemical vapor deposition (CVD) synthetic diamond gemstones
While a spectral line matching the 499 nm wavelength has been previously observed in CVD diamond, this is the first time it has been seen in synthetic gemstonequality material

Summary

Luminescence Data for Synthetic Diamond Gemstones

The only other reference to a spectral line matching this wavelength that we are aware of is in a short communication by Kitawaki et al from the Central Gem Laboratory, Tokyo, concerning measurements made on undisclosed CVD diamond samples.[7] The authors report that under 325 nm excitation, 462 and 499 nm peaks with unknown origins were detected, no spectra were included in this communication to aid comparison. They speculate that the samples may have undergone post-growth HPHT treatment. Able to rule out that luminescent emission at 499 nm occurs on similar fast timescales at room temperature because the prompt blue luminescence may have swamped this weaker signal

Luminescence Comparison with Annealed CVD Diamonds

Discussion

Conclusion

Experimental Section