@article{FuchsStenderTrupkeetal.2015,
  author    = {Fuchs, F. and Stender, B. and Trupke, M. and Simin, D. and Pflaum, J. and Dyakonov, V. and Astakhov, G.V.},
  title     = {Engineering near-infrared single-photon emitters with optically active spins in ultrapure silicon carbide},
  series = {Nature Communications},
  volume    = {6},
  journal   = {Nature Communications},
  number    = {7578},
  doi       = {10.1038/ncomms8578},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148502},
  year      = {2015},
  abstract  = {Vacancy-related centres in silicon carbide are attracting growing attention because of their appealing optical and spin properties. These atomic-scale defects can be created using electron or neutron irradiation; however, their precise engineering has not been demonstrated yet. Here, silicon vacancies are generated in a nuclear reactor and their density is controlled over eight orders of magnitude within an accuracy down to a single vacancy level. An isolated silicon vacancy serves as a near-infrared photostable single-photon emitter, operating even at room temperature. The vacancy spins can be manipulated using an optically detected magnetic resonance technique, and we determine the transition rates and absorption cross-section, describing the intensity-dependent photophysics of these emitters. The on-demand engineering of optically active spins in technologically friendly materials is a crucial step toward implementation of both maser amplifiers, requiring high-density spin ensembles, and qubits based on single spins.},
  language  = {en}
}
@article{AnisimovSiminSoltamovetal.2016,
  author    = {Anisimov, A. N. and Simin, D. and Soltamov, V. A. and Lebedev, S. P. and Baranov, P. G. and Astakhov, G. V. and Dyakonov, V.},
  title     = {Optical thermometry based on level anticrossing in silicon carbide},
  series = {Scientific Reports},
  volume    = {6},
  journal   = {Scientific Reports},
  number    = {33301},
  doi       = {10.1038/srep33301},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147809},
  year      = {2016},
  abstract  = {We report a giant thermal shift of 2.1 MHz/K related to the excited-state zero-field splitting in the silicon vacancy centers in 4H silicon carbide. It is obtained from the indirect observation of the optically detected magnetic resonance in the excited state using the ground state as an ancilla. Alternatively, relative variations of the zero-field splitting for small temperature differences can be detected without application of radiofrequency fields, by simply monitoring the photoluminescence intensity in the vicinity of the level anticrossing. This effect results in an all-optical thermometry technique with temperature sensitivity of 100 mK/Hz\(^{1/2}\) for a detection volume of approximately 10\(^{-6}\) mm\(^3\). In contrast, the zero-field splitting in the ground state does not reveal detectable temperature shift. Using these properties, an integrated magnetic field and temperature sensor can be implemented on the same center.},
  language  = {en}
}
@article{SiminSoltamovPoshakinskiyetal.2016,
  author    = {Simin, D. and Soltamov, V. A. and Poshakinskiy, A. V. and Anisimov, A. N. and Babunts, R. A. and Tolmachev, D. O. and Mokhov, E. N. and Trupke, M. and Tarasenko, S. A. and Sperlich, A. and Baranov, P. G. and Dyakonov, V. and Astakhov, G. V.},
  title     = {All-Optical dc Nanotesla Magnetometry Using Silicon Vacancy Fine Structure in Isotopically Purified Silicon Carbide},
  series = {Physical Review X},
  volume    = {6},
  journal   = {Physical Review X},
  doi       = {10.1103/PhysRevX.6.031014},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147682},
  pages     = {031014},
  year      = {2016},
  abstract  = {We uncover the fine structure of a silicon vacancy in isotopically purified silicon carbide (4H-\(^{28}\)SiC) and reveal not yet considered terms in the spin Hamiltonian, originated from the trigonal pyramidal symmetry of this spin-3/2 color center. These terms give rise to additional spin transitions, which would be otherwise forbidden, and lead to a level anticrossing in an external magnetic field. We observe a sharp variation of the photoluminescence intensity in the vicinity of this level anticrossing, which can be used for a purely all-optical sensing of the magnetic field. We achieve dc magnetic field sensitivity better than 100  nT/√Hz within a volume of 3×10\(^{-7}\)mm\(^3\) at room temperature and demonstrate that this contactless method is robust at high temperatures up to at least 500 K. As our approach does not require application of radio-frequency fields, it is scalable to much larger volumes. For an optimized light-trapping waveguide of 3  mm\(^3\), the projection noise limit is below 100  fT/√Hz.},
  language  = {en}
}
@article{BaumannTvingstedtHeiberetal.2014,
  author    = {Baumann, A. and Tvingstedt, K. and Heiber, M. C. and V{\"a}th, S. and Momblona, C. and Bolink, H. J. and Dyakonov, V.},
  title     = {Persistent photovoltage in methylammonium lead iodide perovskite solar cells},
  series = {APL Materials},
  volume    = {2},
  journal   = {APL Materials},
  number    = {8},
  doi       = {10.1063/1.4885255},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119397},
  pages     = {081501},
  year      = {2014},
  abstract  = {We herein perform open circuit voltage decay (OCVD) measurements on methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells to increase the understanding of the charge carrier recombination dynamics in this emerging technology. Optically pulsed OCVD measurements are conducted on CH3NH3PbI3 solar cells and compared to results from another type of thin-film photovoltaics, namely, the two reference polymer-fullerene bulk heterojunction solar cell devices based on P3HT:PC60BM and PTB7:PC70BM blends. We observe two very different time domains of the voltage transient in the perovskite solar cell with a first drop on a short time scale that is similar to the decay in the studied organic solar cells. However, 65\%-70\% of the maximum photovoltage persists on much longer timescales in the perovskite solar cell than in the organic devices. In addition, we find that the recombination dynamics in all time regimes are dependent on the starting illumination intensity, which is also not observed in the organic devices. We then discuss the potential origins of these unique behaviors.},
  language  = {en}
}
@article{AstakhovFuchsSoltamovetal.2013,
  author    = {Astakhov, Georgy V. and Fuchs, F. and Soltamov, V. A. and V{\"a}th, S. and Baranov, P. G. and Mokhov, E. N. and Dyakonov, V.},
  title     = {Silicon carbide light-emitting diode as a prospective room temperature source for single photons},
  series = {Scientific Reports},
  journal   = {Scientific Reports},
  doi       = {10.1038/srep01637},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96308},
  year      = {2013},
  abstract  = {Generation of single photons has been demonstrated in several systems. However, none of them satisfies all the conditions, e.g. room temperature functionality, telecom wavelength operation, high efficiency, as required for practical applications. Here, we report the fabrication of light-emitting diodes (LEDs) based on intrinsic defects in silicon carbide (SiC). To fabricate our devices we used a standard semiconductor manufacturing technology in combination with high-energy electron irradiation. The room temperature electroluminescence (EL) of our LEDs reveals two strong emission bands in the visible and near infrared (NIR) spectral ranges, associated with two different intrinsic defects. As these defects can potentially be generated at a low or even single defect level, our approach can be used to realize electrically driven single photon source for quantum telecommunication and information processing.},
  language  = {en}
}