June 23, 2020
- The development of photovoltaics, i.e., solar cell materials, based on low-cost, earth-abundant, non-toxic constituents is one of the biggest challenges in energy materials. Pyrite iron disulfide, or Fool’s Gold, has been recognized for over 30 years as a leading contender, but suffers from low output voltage in solar cells.
Research led by graduate student Bryan Voigt in the Leighton Group, working with the group of Eray Aydil at New York University, has now made critical progress by elucidating the source of this low voltage. The team resolved a major inconsistency by detecting, for the first time, an internal p-n junction formed due to the known p-type surface layer on n-type pyrite crystals (see image). It was then shown that this internal junction very likely limited the performance of prior pyrite solar cells, demystifying the low voltage output. Importantly, these findings lead to clear directions for improvement, either utilizing the naturally formed internal junction, or developing new homojunction pyrite solar cells. The work was recently published in ACS Materials Letters, as Voigt, Moore, Maiti, Walter, Das, Manno, Leighton, and Aydil, ACS Materials Lett. 2, 861 (2020).
Related Link: https://pubs.acs.org/doi/10.1021/acsmaterialslett.0c00207