% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@PHDTHESIS{Nuys:276128,
      author       = {Nuys, Maurice René},
      title        = {{C}haracterization $\&$ {M}odification of {C}opper and
                      {I}ron {O}xide {N}anoparticles for {A}pplication as
                      {A}bsorber {M}aterial in {S}ilicon based {T}hin {F}ilm
                      {S}olar {C}ells},
      volume       = {291},
      school       = {RWTH Aachen},
      type         = {Dissertation},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {FZJ-2015-06605},
      isbn         = {978-3-95806-096-8},
      series       = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
                      Umwelt / Energy $\&$ Environment},
      pages        = {XII, 123 S.},
      year         = {2015},
      note         = {Dissertation, RWTH Aachen, 2015},
      abstract     = {The present thesis deals with the characterization and
                      modication of semiconductingcopper oxide (CuO, Cu$_{2}$O)
                      and iron oxide ($\gamma$-Fe$_{2}$O$_{3}$,
                      $\alpha$-Fe$_{2}$O$_{3}$) nanoparticles, which provide a
                      basis for an innovative solar cell concept involving
                      nanoparticles composed of almost unlimitedly available
                      elements as absorber material in thin film solar cells. This
                      approach is promising to meet the requirements of increasing
                      the production capacity and lowering the production costs if
                      the nanoparticles exhibit superior properties compared to
                      corresponding thin films. Therefore, the goal of this thesis
                      is to demonstrate the high quality of semiconducting
                      nanoparticles that can be achieved by proper treatment. The
                      structural and opto-electronic properties of copper as well
                      as iron oxide compounds are investigated and the inuence of
                      thermal annealing is analyzed. Commercially available
                      tenorite (CuO) nanoparticles with a diameter of about 30nm
                      are annealed stepwise up to 1000 C in air and nitrogen
                      atmosphere. The photoluminescence (PL) and photothermal
                      deflection spectroscopy (PDS) results show tenorite band
                      emission at about 1.3 eV, which strongly increases
                      accompanied by a decreasing sub gap absorption with
                      increasing annealing temperature up to 700 C and 1000 C in
                      nitrogen atmosphere and air, respectively. These variations
                      are ascribed to a reduction of the defect concentration.
                      According to literature, a phase transition from tenorite to
                      cuprite (Cu$_{2}$O) is expected and observed after annealing
                      at 800 $^{\circ}$C in nitrogen atmosphere. Strong cuprite
                      band edge emission at about 2 eV accompanied by very weak
                      defect and possibly tenorite band edge emission is found for
                      the samples annealed at 800 $^{\circ}$C and 1000
                      $^{\circ}$C. Analyzing selected Raman and PDS spectra of the
                      nanoparticles annealed at 800 $^{\circ}$C, the volume
                      fraction of a remaining tenorite phase is estimated to be
                      smaller than 20\%. There is noindication for the presence of
                      tenorite after annealing at 1000 $^{\circ}$C. In comparison
                      to results reported for tenorite bulk material and thin
                      films, nanoparticlesinclude fewer defects and therefore show
                      superior opto-electronic properties. The cuprite
                      nanoparticles exhibit excellent properties at least similar
                      to high qualitysingle crystals. In contrast to results
                      usually reported in the literature for cuprite thin films,
                      the PL spectra are not dominated by strongly pronounced
                      defect emission,which confirms that high quality
                      nanoparticles can be easier prepared than corresponding thin
                      films. Likewise, commercially available maghemite
                      ($\gamma$-Fe$_{2}$O$_{3}$) nanoparticles with a diameter of
                      about 8nm to 15 nm are modified by oven annealing in
                      nitrogen atmosphere up to 900 $^{\circ}$C. The PDS and PL
                      results of as-prepared nanoparticles indicate the band gap
                      at about 2 eV and a weakly pronounced and broad emission in
                      the spectral regionof the band gap. Up to an annealing
                      temperature of 450 $^{\circ}$C, the nanoparticles remain in
                      the maghemite phase and their opto-electronic properties are
                      only weakly affected. The PDS spectra reveal typical
                      absorption features that are ascribed to ligand field
                      transitions at about 1.4 eV and 1.9 eV. After further
                      annealing at 550 $^{\circ}$C, [...]},
      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},
      urn          = {urn:nbn:de:0001-2016022919},
      url          = {https://juser.fz-juelich.de/record/276128},
}