Photovoltaic effect for narrow-gap Mott insulators

  title={Photovoltaic effect for narrow-gap Mott insulators},
  author={Efstratios Manousakis},
  journal={Physical Review B},
We discuss the photovoltaic effect at a p-n heterojunction, in which the illuminated side is a doped Mott insulator, using the simplest description of a Mott insulator within the Hubbard model. We find that the internal quantum efficiency of such a device, if we choose an appropriate narrow-gap Mott insulator, can be significantly enhanced due to impact ionization caused by the photoexcited ``hot'' electron/hole pairs. Namely, the photoexcited electron and/or hole can convert its excess energy… 

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