Abstract
The incorporation of Eu into the diamond lattice is investigated in a combined theoretical experimental study. The large size of the Eu ion induces a strain on the host lattice, which is minimal for the Eu-vacancy complex. The oxidation state of Eu is calculated to be 3+ for all defect models considered. In contrast, the total charge of the defect-complexes is shown to be negative: -1.5 to -2.3 electron. Hybrid-functional electronic-band structures show the luminescence of the Eu defect to be strongly dependent on the local defect geometry. The 4-coordinated Eu substitutional dopant is the most promising candidate to present the typical Eu3+ luminescence, while the 6-coordinated Eu-vacancy complex is expected not to present any luminescent behaviour. Preliminary experimental results on the treatment of diamond films with Eu-containing precursor indicate the possible incorporation of Eu into diamond films treated by drop-casting. Changes in the PL spectrum, with the main luminescent peak shifting from approximately 614 nm to 611 nm after the growth plasma exposure, and the appearance of a shoulder peak at 625 nm indicate the potential incorporation. Drop-casting treatment with an electronegative polymer material was shown not to be necessary to observe the Eu signature following the plasma exposure, and increased the background luminescence.
Original language | English |
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Pages (from-to) | 233-241 |
Number of pages | 9 |
Journal | Diamond and Related Materials |
Volume | 94 |
DOIs | |
Publication status | Published - Apr 2019 |
Keywords
- Diamond
- Eu
- Doping
- Defects
- DFT
- Density functional theory
- Electronic structure
- Phonons
- Photoluminescence
- DENSITY-FUNCTIONAL THEORY
- EXTENDING HIRSHFELD-I
- ELECTRONIC-STRUCTURE
- VACANCY
- FRAMEWORKS
- BULK