Micro-photoluminescence analysis of the redistribution of NV and SV defects in individual CVD diamond microcrystal with the distance from Si substrate

DOI: 10.62564/M4-IN1124

Iurii Nasieka^1,2, Volodymyr Strel’nitskij³, Oksana Horobei¹, Volodymyr Lozinskii¹, Volodymyr Temchenko<sup>1

1</sup>V. Lashkaryov Institute of Semiconductor Physics of National Academy of Science of Ukraine
²National University of Life and Environmental Sciences of Ukraine
³National Science Center “Kharkov Institute of Physics and Technology”, Ukraine


The vertical distribution of NV-, NV0 and SiV defects in the individual 60 µm height diamond microcrystal of PECVD film grown on Si single crystalline substrate was studied using the micro-photoluminescence method. The presence of N-related defects in the studied crystal is caused by the imperfection of the PECVD vacuum system [1]. The excitation of micro-photoluminescence signals was carried out using the 2.54 eV (488 nm) Ar-Kr laser line focused by the microscope 100x objective in the spot with the diameter equal to 2 µm. The changes in the shape of room-temperature micro-photoluminescence spectra of diamond micro-crystal measured, depending on the position of focused laser excitation spot along the crystallite height, were analyzed. All spectra were deconvoluted on the elementary Lorentzians including zero-phonon luminescence bands related to each NV-, NV0 and SiV defects and their phonon replicas. Comparing the emission bands intensity the area under the corresponding elementary contours was calculated. It was obtained that the processes of SiV defects formation non-monotonically depends on the distance from Si substrate. At the distances of 2 – 20 µm the concentration of SiV defects increases sharply, then at the distances larger than 20 µm the number of SiV defects decreases. The concentration of NV- and NV0 defects monotonically increase with increase in the distance from the Si substrate. The predomination of SiV defects formation at the beginning stages of the crystal growth is explained by the substantial density of carbon divacancies required their formation. With increase in the distance from the substrate the crystalline perfection increases, the number of carbon divacancies decrease and the processes of NV- and NV0 defects formation dominates. The obtained results are important for the developers of CVD diamond film based sensors, which performance is defined by the concentration and distribution of NV-, NV0 and SiV optical centers.

Keywords
PECVD method; diamond microcrystal; Micro-photoluminescence; Optical centers.

Acknowledgments
Not provided

References
[1] Iu. Nasieka, E. Strelnitskij, O. Opalev, V. Gritsina, K. Koshevyi, O. Horobei, V. Lementaryov, V. Trokhaniak, M. Boyko, Difference in the structure and morphology of CVD diamond films grown on negatively charged and grounded substrate holders: Optical study, SPQEO, 2024. V. 27, No 1. P. 079-089.