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Descripción
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| An increase in PV efficiency (ideally, from the 40.7% Queisser limit to a 63.2%) has been proposed to be possible using intermediate band (IB) materials, in which an electron can jump from the valence band (VB) to the conduction band (CB) upon absorption of two sub-bandgap energy photons if a partially filled, isolated IB exists between the VB and CB. With DFT simulations we have proposed that partial substitution of Ga by Ti or Cr in GaAs, GaP or CuGaS2 can lead to this property. Our more recent work shows that this can be achieved also substituting by Ti or V the octahedrally coordinated cations in In2S3 (with bandgap Eg=2.0 eV, close to optimum for this purpose) and related materials. This octahedral geometry would allow to insert high metal amounts (in the 10% range), leading to stronger sub-bandgap light response than is possible with other proposed IB schemes. Here we present an overview of different systems where the IB can be achieved in this way according to our DFT calculations, that can predict their band structures and optical absorption spectra, and show the experimental realization of several such materials, mainly of sulphide class, whose optical spectra show for the first time the strong IB-based sub-bandgap photon absorption features predicted for them by DFT. | |
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Internacional
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Si |
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Nombre congreso
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12th International Conference on Modern Materials and Technologies (CIMTEC 2010) - 5th Forum on New Materials |
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Tipo de participación
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960 |
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Lugar del congreso
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Montecatini Terme, Tuscany (Italia) |
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Revisores
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Si |
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ISBN o ISSN
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00-0000-000-0 |
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DOI
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Fecha inicio congreso
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13/06/2010 |
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Fecha fin congreso
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18/06/2010 |
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Desde la página
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1 |
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Hasta la página
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4 |
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Título de las actas
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Proc. CIMTEC 2010 |