@article{VollbrechtBrus2020,
  author    = {Vollbrecht, Joachim and Brus, Viktor V.},
  title     = {On charge carrier density in organic solar cells obtained via capacitance spectroscopy},
  series = {Advanced electronic materials},
  volume    = {6},
  journal   = {Advanced electronic materials},
  number    = {10},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2199-160X},
  doi       = {10.1002/aelm.202000517},
  pages     = {9},
  year      = {2020},
  abstract  = {The determination of the voltage-dependent density of free charge carriers via capacitance spectroscopy is considered an important step in the analysis of emerging photovoltaic technologies, such as organic and perovskite solar cells. In particular, an intimate knowledge of the density of free charge carriers is required for the determination of crucial parameters such as the effective mobility, charge carrier lifetime, nongeminate recombination coefficients, average extraction times, and competition factors. Hence, it is paramount to verify the validity of the commonly employed approaches to obtain the density of free charge carriers. The advantages, drawbacks, and limitations of the most common approaches are investigated in detail and strategies to mitigate misleading values are explored. To this end, two types of nonfullerene organic solar cells based on a PTB7-Th:ITIC-2F blend and a PM6:Y6 blend, respectively, are used as a case study to assess how subsequent analyses of the nongeminate recombination dynamics depend on the chosen approach to calculate the density of free charge carriers via capacitance spectroscopy.},
  language  = {en}
}
@article{VerganiCarminatiFerrarietal.2012,
  author    = {Vergani, Marco and Carminati, Marco and Ferrari, Giorgio and Landini, Ettore and Caviglia, Claudia and Heiskanen, Arto and Comminges, Clement and Zor, Kinga and Sabourin, David and Dufva, Martin and Dimaki, Maria and Raiteri, Roberto and Wollenberger, Ursula and Emneus, Jenny and Sampietro, Marco},
  title     = {Multichannel bipotentiostat integrated with a microfluidic platform for electrochemical real-time monitoring of cell cultures},
  series = {IEEE Transactions on biomedical circuits and systems},
  volume    = {6},
  journal   = {IEEE Transactions on biomedical circuits and systems},
  number    = {5},
  publisher = {Inst. of Electr. and Electronics Engineers},
  address   = {Piscataway},
  issn      = {1932-4545},
  doi       = {10.1109/TBCAS.2012.2187783},
  pages     = {498 -- 507},
  year      = {2012},
  abstract  = {An electrochemical detection system specifically designed for multi-parameter real-time monitoring of stem cell culturing/differentiation in a microfluidic system is presented. It is composed of a very compact 24-channel electronic board, compatible with arrays of microelectrodes and coupled to a microfluidic cell culture system. A versatile data acquisition software enables performing amperometry, cyclic voltammetry and impedance spectroscopy in each of the 12 independent chambers over a 100 kHz bandwidth with current resolution down to 5 pA for 100 ms measuring time. The design of the platform, its realization and experimental characterization are reported, with emphasis on the analysis of impact of input capacitance (i.e., microelectrode size) and microfluidic pump operation on current noise. Programmable sequences of successive injections of analytes (ferricyanide and dopamine) and rinsing buffer solution as well as the impedimetric continuous tracking for seven days of the proliferation of a colony of PC12 cells are successfully demonstrated.},
  language  = {en}
}
@article{WagnerLazarSchnakenbergetal.2016,
  author    = {Wagner, Tom and Lazar, Jaroslav and Schnakenberg, Uwe and B{\"o}ker, Alexander},
  title     = {In situ Electrothemical Impedance Spectroscopy of Electrostatically Driven Selective Gold Nanoparticle Adsorption on Block Copolymer Lamellae},
  series = {Trials},
  volume    = {8},
  journal   = {Trials},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1944-8244},
  doi       = {10.1021/acsami.6b07708},
  pages     = {27282 -- 27290},
  year      = {2016},
  abstract  = {Electrostatic attraction between charged nano particles and oppositely charged nanopatterned polymeric films enables tailored structuring of functional nanoscopic surfaces. The bottom-up fabrication of organic/inorganic composites for example bears promising potential toward cheap fabrication of catalysts, optical sensors, and the manufacture of miniaturized electric circuitry. However, only little is known about the time-dependent adsorption behavior and the electronic or ionic charge transfer in the film bulk and at interfaces during nanoparticle assembly via electrostatic interactions. In situ electrochemical impedance spectroscopy (EIS) in combination with a microfluidic system for fast and reproducible liquid delivery was thus applied to monitor the selective deposition of negatively charged gold nanoparticles on top of positively charged poly(2-vinylpyridinium) (qP2VP) domains of phase separated lamellar poly(styrene)-block-poly(2-vinylpyridinium) (PS-b-qP2VP) diblock copolymer thin films. The acquired impedance data delivered information with respect to interfacial charge alteration, ionic diffusion, and the charge dependent nanoparticle adsorption kinetics, considering this yet unexplored system. We demonstrate that the selective adsorption of negatively charged gold nanoparticles (AuNPs) on positively charged qP2VP domains of lamellar PS-b-qP2VP thin films can indeed be tracked by EIS. Moreover, we show that the nanoparticle adsorption kinetics and the nanoparticle packing density are functions of the charge density in the qP2VP domains.},
  language  = {en}
}