The present work is focused on the in-situ characterization of defects in single-crystal diamond induced by 6 MeV carbon ion beam irradiation using ionoluminescence (IL) spectroscopy. The main purpose was to study the optical properties of several defects following the IL evolution and characterize the damage degree using Raman spectra. Three emissions were recorded by IL spectra, located at 430, 504, 575.5 nm with ion fluence in the range of 0∼7 × 1014 cm−2, and were attributed to the A-band, 3H, and NV0 centers, respectively. The 3H centers exhibited a non-monotonic behavior with respect to fluence, with a rapid initial increase followed by a gradual decay. Based on a double exponential model, the data had been well-fitted, and the value of fluence at half of the initial luminescence (F1/2) was found to be notably high (of order 1014 cm−2). A simple Birks-Black model was applied to fit the evolution of the A-band and NV0 centers, and luminescence decays were observed with F1/2 values of (7.9 ± 2.2) × 1011 and (1.2 ± 0.6) × 1012 cm−2, respectively. At the initial stage of irradiation, the intensity decay of A-band and NV0 centers is accompanied by an increase of 3H centers, suggesting that there is a conversion between the defect types.

This work was supported by China Scholarship Council (CSC, File No. 202308140156), National Natural Science Foundation of China (Grant No. U21A2073, 62304175), Shanxi Province Natural Science Foundation (Grant Nos. 202203021222207, 202203021211210, 202103021224268), the Taiyuan University of Science and Technology Research Initiation Fund Project (Grant Nos. 20222065, 20222005), the European Union as part of the Horizon Europe call HORIZON-INFRA- 2021-SERV-01 (Grant No. 101058414), co-funded by UK UKRI (Grant No. 10039728), the Swiss State Secretariat for Education, Research and Innovation (SERI) (Grant No. 22.00187), the Spanish Ministry of Science and Innovation (MICINN) (Grant No. PID2022-142417OB-I00 and PID2020-112770RB-C22), and the Madrid Regional Government through the TechnoFusion (III)-CM program (Grant No. S2018/EMT- 4437). The authors acknowledge the support from The Centro de Microanalisis de Materiales (CMAM) - Universidad Autonoma de Madrid, for the beam time proposals IMP- 006/24, and its technical staff for their contribution to the operation of the accelerator.

7 pages, 8 figures, 2 tables

Peer reviewed