@article{WeissenseelGottschollBoennighausenetal.2021,
  author    = {Weissenseel, Sebastian and Gottscholl, Andreas and B{\"o}nnighausen, Rebecca and Dyakonov, Vladimir and Sperlich, Andreas},
  title     = {Long-lived spin-polarized intermolecular exciplex states in thermally activated delayed fluorescence-based organic light-emitting diodes},
  series = {Science Advances},
  volume    = {7},
  journal   = {Science Advances},
  number    = {47},
  doi       = {10.1126/sciadv.abj9961},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265508},
  year      = {2021},
  abstract  = {Spin-spin interactions in organic light-emitting diodes (OLEDs) based on thermally activated delayed fluorescence (TADF) are pivotal because radiative recombination is largely determined by triplet-to-singlet conversion, also called reverse intersystem crossing (RISC). To explore the underlying process, we apply a spin-resonance spectral hole-burning technique to probe electroluminescence. We find that the triplet exciplex states in OLEDs are highly spin-polarized and show that these states can be decoupled from the heterogeneous nuclear environment as a source of spin dephasing and can even be coherently manipulated on a spin-spin relaxation time scale T-2* of 30 ns. Crucially, we obtain the characteristic triplet exciplex spin-lattice relaxation time T-1 in the range of 50 mu s, which far exceeds the RISC time. We conclude that slow spin relaxation rather than RISC is an efficiency-limiting step for intermolecular donor:acceptor systems. Finding TADF emitters with faster spin relaxation will benefit this type of TADF OLEDs.},
  language  = {en}
}
@article{GottschollDiezSoltamovetal.2021,
  author    = {Gottscholl, Andreas and Diez, Matthias and Soltamov, Victor and Kasper, Christian and Krauße, Dominik and Sperlich, Andreas and Kianinia, Mehran and Bradac, Carlo and Aharonovich, Igor and Dyakonov, Vladimir},
  title     = {Spin defects in hBN as promising temperature, pressure and magnetic field quantum sensors},
  series = {Nature Communications},
  volume    = {12},
  journal   = {Nature Communications},
  number    = {1},
  doi       = {10.1038/s41467-021-24725-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261581},
  year      = {2021},
  abstract  = {Spin defects in solid-state materials are strong candidate systems for quantum information technology and sensing applications. Here we explore in details the recently discovered negatively charged boron vacancies (V\(_B\)\(^-\)) in hexagonal boron nitride (hBN) and demonstrate their use as atomic scale sensors for temperature, magnetic fields and externally applied pressure. These applications are possible due to the high-spin triplet ground state and bright spin-dependent photoluminescence of the V\(_B\)\(^-\). Specifically, we find that the frequency shift in optically detected magnetic resonance measurements is not only sensitive to static magnetic fields, but also to temperature and pressure changes which we relate to crystal lattice parameters. We show that spin-rich hBN films are potentially applicable as intrinsic sensors in heterostructures made of functionalized 2D materials.},
  language  = {en}
}