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We addressed the carrier dynamics in so-called G-centers in silicon (consisting of substitutional-interstitial carbon pairs interacting with interstitial silicons) obtained via ion implantation into a silicon-on-insulator wafer. For this point defect in silicon emitting in the telecommunication wavelength range, we unravel the recombination dynamics by time-resolved photoluminescence spectroscopy. More specifically, we performed detailed photoluminescence experiments as a function of excitation energy, incident power, irradiation fluence and temperature in order to study the impact of radiative and non-radiative recombination channels on the spectrum, yield and lifetime of G-centers. The sharp line emitting at 969 meV ($\sim$1280 nm) and the broad asymmetric sideband developing at lower energy share the same recombination dynamics as shown by time-resolved experiments performed selectively on each spectral component. This feature accounts for the common origin of the two emission bands which are unambiguously attributed to the zero-phonon line and to the corresponding phonon sideband. In the framework of the Huang-Rhys theory with non-perturbative calculations, we reach an estimation of 1.6$\pm$0.1 $\angstrom$ for the spatial extension of the electronic wave function in the G-center. The radiative recombination time measured at low temperature lies in the 6 ns-range. The estimation of both radiative and non-radiative recombination rates as a function of temperature further demonstrate a constant radiative lifetime. Finally, although G-centers are shallow levels in silicon, we find a value of the Debye-Waller factor comparable to deep levels in wide-bandgap materials. Our results point out the potential of G-centers as a solid-state light source to be integrated into opto-electronic devices within a common silicon platform

The fabrication of luminescent defects in single-crystal diamond upon Sn implantation and annealing is reported. The relevant spectral features of the optical centers (emission peaks at 593.5, 620.3, 630.7, and 646.7 nm) are attributed to Sn-related defects through the correlation of their photoluminescence (PL) intensity with the implantation fluence. Single Sn-related defects were identified and characterized through the acquisition of their second-order autocorrelation emission functions, by means of Hanbury-Brown and Twiss interferometry. The investigation of their single-photon emission regime as a function of excitation laser power revealed that Sn-related defects are based on three-level systems with a 6 ns radiative decay lifetime. In a fraction of the studied centers, the observation of a blinking PL emission is indicative of the existence of a dark state. Furthermore, absorption dependence on the polarization of the excitation radiation with ∼45% contrast was measured. This work shed light on the existence of a new optical center associated with a group-IV impurity in diamond, with similar photophysical properties to the already well-known Si–V and Ge–V emitters, thus, providing results of interest from both the fundamental and applicative points of view.

Color centers in diamonds have shown promising potential for luminescent thermometry. So far, the nitrogen-vacancy (NV) color center has demonstrated a high sensitivity for optical temperature monitoring in biological systems. However, the NV center requires microwave excitation which can cause unwanted heating, and the NV is also sensitive to non-axial magnetic fields, both of which can result in inaccurate temperature measurements. To overcome this drawback, the silicon-vacancy (SiV) and germanium-vacancy (GeV) color centers in diamonds have recently been explored and have shown good optical temperature sensitivity owing to the temperature dependent wavelength optical zero-phonon line. Here, we report optical temperature measurements using the recently discovered tin-vacancy (SnV) color center in diamond and show sensitivity better than 0.2 K in 10 s integration time. Also, we compare the relative merits of SnV with respect to SiV and GeV for luminescent thermometry. These results illustrate that there are likely to be many future options for nanoscale thermometry using diamonds.

We report the detection of individual emitters in silicon belonging to seven different families of optically active point defects. These fluorescent centers are created by carbon implantation of a commercial siliconon-insulator wafer usually employed for integrated photonics. Single photon emission is demonstrated over the 1.1-1.55 μm range, spanning the O and C telecom bands. We analyze their photoluminescence spectra, dipolar emissions, and optical relaxation dynamics at 10 K. For a specific family, we show a constant emission intensity at saturation from 10 K to temperatures well above the 77 K liquid nitrogen temperature. Given the advanced control over nanofabrication and integration in silicon, these individual artificial atoms are promising systems to investigate for Si-based quantum technologies.