Photo-physical properties of He-related color centers in diamond

Abstract

Diamond is a promising platform for the development of technological applications in quantum optics and photonics. The quest for color centers with optimal photo-physical properties has led in recent years to the search for novel impurity-related defects in this material. Here, we report on a systematic investigation of the photo-physical properties of two He-related (HR) emission lines at 535 nm and 560 nm created in three different diamond substrates upon implantation with 1.3 MeV He + ions and subsequent annealing. The spectral features of the HR centers were studied in an "optical grade" diamond substrate as a function of several physical parameters, namely the measurement temperature, the excitation wavelength and the intensity of external electric fields. The emission lifetimes of the 535 nm and 560 nm lines were also measured by means of time-gated photoluminescence measurements, yielding characteristic decay times of (29 ± 5) ns and (106 ± 10) ns, respectively. The Stark shifting of the HR centers under the application of an external electrical field was observed in a CVD diamond film equipped with buried graphitic electrodes, suggesting a lack of inversion symmetry in the defects' structure. Furthermore, the photoluminescence mapping under 405 nm excitation of a "detector grade" diamond sample implanted at a 1×10 10 cm -2 He + ion fluence enabled to identify the spectral features of both the HR emission lines from the same localized optical spots. The reported results provide a first insight towards the understanding of the structure of He-related defects in diamond and their possible utilization in practical applications. MAIN TEXTColor centers in diamond are appealing physical systems for application in emerging quantum technologies. In recent years, a growing interest in this research field led to the discovery, investigation and fabrication of several classes of impurity-related defects [1][2][3][4][5][6][7][8].The formation of optically active defects in diamond upon He implantation followed by annealing in vacuum was recently reported [9]. The spectral features of these defects consist of two narrow emission lines at 536 nm and 560.5 nm, and a phonon sideband in the 572-630 nm spectral range. Following their initial observation in cathodoluminescence (CL) [10,11], their optical activity was investigated in both photoluminescence (PL) and electroluminescence (EL) [9,12]. The need of understanding the possible formation of stable optically active centers, whose current (and still tentative) attribution is based on He incorporation in the diamond lattice, motivates a further investigation of their opto-physical properties. More specifically, the centers have so far been attributed to the He-vacancy complex [13], and density functional theory calculations demonstrated that both this structure and the interstitial He defect could result in stable complexes in the diamond lattice [14]. Apart from this limited body of works, a systematic set of experimental results on the characterization of the ...

Screening and engineering of colour centres in diamond

“…Native centres emitting in the near-infrared were also reported from commercially available diamond samples treated thermally [29] without knowing what they are made of. Note that fluorescent centres related to Europium [30] and Helium [31,32] were recently reported. Therefore, a large number of optically active defects has been observed in diamond establishing this material as a promising platform for exploring properties at the quantum scale.…”

Color centres in diamond from single photon sources to ODMR in cells

“…In this case, an extensive study of samples incorporating Helium realated centers was performed and their photo-physical properties were investigated as a function of several parameters (temperature, excitation wavelength amd intensity of external electrical fields). 14 In particular, emission lines at 535.2 nm (He1) and 559.7 nm (He2) were observed in three samples after 1.3 MeV He + implantation. The mean emission lifetimes for the two PL lines were measured as, respectively, τ He1 = (29 ± 5) ns and τ He2 = (106 ± 10) ns.…”

“…The work is structured as follows: in Sec. 1 the efforts for the realization of novel SPSs based on Sn-and He-related color centers 13,14 in diamond will be described; In Sec. 2, the results on the implementation of an electrically-pumped 15 SPS based on NV centers will be shown; Sec.…”

Spectral Emission Dependence of Tin‐Vacancy Centers in Diamond from Thermal Processing and Chemical Functionalization

“…[24][25][26] The PL emission of individual SnV centers was characterized by means of a fiber-coupled single-photon sensitive room-temperature confocal microscope already presented in previous works. [27] The confocal microscope was operated using a 520 nm CW laser excitation. A 600 nm long-pass filter enabled the minimization of the background associated with the Raman scattering (567 nm); at the same time, it prevented the investigation of the 593 nm emission line reported in previous works.…”