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@PHDTHESIS{Wilken:830198,
      author       = {Wilken, Karen},
      title        = {{L}ow {T}emperature {T}hin-{F}ilm {S}ilicon {S}olar {C}ells
                      on {F}lexible {P}lastic {S}ubstrates},
      volume       = {377},
      school       = {RWTH Aachen},
      type         = {Dr.},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek Verlag},
      reportid     = {FZJ-2017-03772},
      isbn         = {978-3-95806-235-1},
      series       = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
                      Umwelt / Energy $\&$ Environment},
      pages        = {194 S.},
      year         = {2017},
      note         = {RWTH Aachen, Diss., 2017n},
      abstract     = {Providing energy for a steadily increasing world population
                      is one of the major tasks of our time. Solar energy has the
                      ability to satisfy this demand in a clean, sustainable and
                      environmentally friendly manner. Though solar module prices
                      have fallen considerably within the last years, costs need
                      to be further reduced to achieve comprehensive gridparity. A
                      possible approach for reduced module costs is provided by
                      thin-film technologies and the use of low cost polymer
                      substrates. In addition, this research eld offers the
                      opportunity to provide exible and lightweight solar modules,
                      gaining increasing attention for applications in building
                      integrated photovoltaics, exible electronics and mobile
                      power applications. Roll-to-roll manufacturing in turn
                      provides an additional tool for possible cost reductions by
                      high-throughput production. The use of low cost transparent
                      plastic films enables to produce solar cells in the socalled
                      superstrate concept, where sunlight enters through the
                      substrate. However, these types of substrates limit the
                      applicable process temperature range. The aim of this thesis
                      is to investigate the in uence of low deposition
                      temperatures (120 $^{\circ}$C) on the properties of
                      functional layers and to establish a link between material
                      properties and the performance of thin-film silicon solar
                      cells on plastic substrates. This work demonstrates that the
                      deterioration in electrical properties of amorphous silicon
                      (a-Si:H) layers, due to a lower deposition temperature, can
                      be compensated by careful adjustment of deposition gas ow
                      mixtures, resulting in an efficiency of 9.1\% for an a-Si:H
                      solar cell on glass substrate. Microcrystalline silicon
                      ($\mu$c-Si:H) layers are less sensitive to a reduction in
                      deposition temperature and by implementation in an
                      a-Si:H/$\mu$c-Si:H tandem solar cell, an efficiency of 9.8\%
                      was achieved with great potential for future improvement.
                      The low temperature a-Si:H solar cells exhibit a strong
                      improvement in all photovoltaic parameters, particularly in
                      the fill factor, after post-deposition annealing at 120
                      $^{\circ}$C. Extensive studies were carried out to
                      understand the underlying physical processes and to link the
                      changes in individual layers upon annealing to changes in
                      solar cell performance. Changes in layer properties were
                      investigated as a function of annealing time and consequent
                      in uence on the solar cell performance was analyzed.
                      Measurements of external quantum efficiencies of p- as well
                      as n-side illuminated solar cells in addition to variable
                      intensity measurements revealed a strong positive effect of
                      the post-deposition annealing on the charge carrier
                      collection efficiency. Possible contributions from the $\mu
                      \tau$-products of electrons and holes in the intrinsic
                      absorber layer, as well as the built-in field in the solar
                      cell were analyzed and discussed, and supported by computer
                      simulations. Annealing effects present in a-Si:H solar cells
                      on PET substrates and $\mu$c-Si:H solar cells on glass
                      substrates were treated as well.},
      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/830198},
}