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@PHDTHESIS{Flohre:834432,
      author       = {Flohre, Jan},
      title        = {{C}harakterisierung und {M}odifizierung von {K}upferoxid-
                      und {K}upfersulfid-{N}anopartikeln für
                      {D}ünnschichtsolarzellen},
      volume       = {379},
      school       = {RWTH Aachen},
      type         = {Dr.},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {FZJ-2017-04388},
      isbn         = {978-3-95806-241-2},
      series       = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
                      Umwelt / Energy $\&$ Environment},
      pages        = {141, ii S.},
      year         = {2017},
      note         = {RWTH Aachen, Diss., 2016},
      abstract     = {The present thesis deals with the characterization and
                      modification of semiconducting copper oxide and copper
                      sulfide nanoparticles with respect to their use as active
                      absorber material in an innovative solar cell concept. The
                      well-established silicon based thin-film solar cell
                      technology can be the basis for this concept and provides
                      cost-effective production. Important requirements for the
                      industrial relevance of the investigated materials, such as
                      being earth abundant, environmentally friendly, as well as
                      possessing both high absorption coeficients and suitable
                      band gaps are fulfilled. The advantage of the concept is the
                      decoupling of the nanoparticle absorber material
                      optimization process from the module production. In this
                      way, nanoparticles with high electronic quality can be
                      prepared by high temperature processes or in chemically
                      reactive environment while the subsequent module production
                      is realized by economic processes at low temperature.
                      Previous works have shown that proper annealing of the
                      copper(II) oxide (CuO) nanoparticles leads to high quality
                      material with respect to optoelectronic properties. In
                      particular, in reducing atmosphere at high temperatures the
                      phase transformation from CuO to copper(I) oxide (Cu$_{2}$O)
                      is possible. In the current thesis it is shown that laser
                      annealing in air leads to an improved micro-structure and a
                      reduced defect density of the CuO nanoparticles.
                      Furthermore, laser annealing in nitrogen atmosphere can
                      transform the starting material into Cu$_{2}$O. Laser
                      annealing has the advantage that selective parts of the
                      sample can be modified. Thus, substrates that are not
                      resistant to high temperature can be used and e.g. a post
                      treatment of the particles in the solar cell is possible.
                      Moreover, a CuO sample transformed into Cu$_{2}$O by
                      annealing at 1000 $^{\circ}$C in nitrogen atmosphere is
                      investigated by micro Raman and photoluminescence (PL)
                      scanning measurements. It is shown, that the variation of
                      structural properties is low while the variation of the
                      electronic properties, in particular the defect structure,
                      is very large. The characterization of the defect structure
                      is realized by studying PL spectra, which were taken at a
                      sample temperature of 93 K. Here, emission bands of
                      different defect transitions, as well as excitonic
                      transitions are detected and identified. The analysis of PL
                      spectra taken at sample temperatures between 93K to 290K
                      made it possible to calculate the excitonic band gap and the
                      full width at half maximum of the excitonic emission. Stress
                      in the crystal and the defect concentration are found to
                      have an impact to these quantities. Therefore, the values
                      are compared to those found in the literature of pure
                      Cu$_{2}$O bulk material. The comparison reveals an higher
                      defect concentration for the investigated Cu$_{2}$O [...]},
      cin          = {IEK-5},
      cid          = {I:(DE-Juel1)IEK-5-20101013},
      pnm          = {121 - Solar cells of the next generation (POF3-121)},
      pid          = {G:(DE-HGF)POF3-121},
      typ          = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
      url          = {https://juser.fz-juelich.de/record/834432},
}