Band Gap of Pb(Fe0.5Nb0.5)O3 Thin Films Prepared by Pulsed Laser Deposition

Nicole Bartek; Vladimir V Shvartsman; Houssny Bouyanfif; Alexander Schmitz; Gerd Bacher; Selina Olthof; Svetlana Sirotinskaya; Niels Benson; Doru C Lupascu

doi:10.3390/ma14226841

Band Gap of Pb(Fe_0.5Nb_0.5)O₃ Thin Films Prepared by Pulsed Laser Deposition

Materials (Basel). 2021 Nov 12;14(22):6841. doi: 10.3390/ma14226841.

Authors

Nicole Bartek¹, Vladimir V Shvartsman¹, Houssny Bouyanfif², Alexander Schmitz³, Gerd Bacher³, Selina Olthof⁴, Svetlana Sirotinskaya⁵, Niels Benson⁵, Doru C Lupascu¹

Affiliations

¹ Institute for Materials Science, Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 45141 Essen, Germany.
² Laboratoire de Physique de la Matière Condensée UR2081, Université de Picardie Jules Verne, 80039 Amiens, France.
³ Electronic Materials and Nanostructures and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 47057 Duisburg, Germany.
⁴ Institute for Physical Chemistry, University of Cologne, 50939 Cologne, Germany.
⁵ Institute of Technology for Nanostructures, Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 47057 Duisburg, Germany.

Abstract

Ferroelectric materials have gained high interest for photovoltaic applications due to their open-circuit voltage not being limited to the band gap of the material. In the past, different lead-based ferroelectric perovskite thin films such as Pb(Zr,Ti)O₃ (Pb,La)(Zr,Ti)O₃ and PbTiO₃ were investigated with respect to their photovoltaic efficiency. Nevertheless, due to their high band gaps they only absorb photons in the UV spectral range. The well-known ferroelectric PbFe_0.5Nb_0.5O₃ (PFN), which is in a structure similar to the other three, has not been considered as a possible candidate until now. We found that the band gap of PFN is around 2.75 eV and that the conductivity can be increased from 23 S/µm to 35 S/µm during illumination. The relatively low band gap value makes PFN a promising candidate as an absorber material.

Keywords: band gap; lead iron niobate; optical properties; photovoltaics; pulsed laser deposition; thin films.

Grants and funding

406710712/Deutsche Forschungsgemeinschaft