Novel nanomaterials for next-generation solar cells

  • Slavia Deeksha Dsouza

Student thesis: Doctoral Thesis


Solar energy is a suitable option for clean energy considering the abundant supply and low environmental impact. Despite of the tremendous growth rate of the photovoltaic industry, there is a need to increase the efficiency for converting photons into useful energy, in addition to making them cheaper, more sustainable, and environmentallyfriendly in terms of materials used and fabrication processes. Emerging nanomaterials as absorbers play an important role in laying the foundation for next-generation solar cells to become a reality due to their highly favourable characteristics and manipulation of their
chemical composition which can lead to interesting properties like tunable bandgap, band-alignment engineering, as well as ease of integration into devices.

Nitrogen-doped carbon quantum dots (N-CQDs) and manganese-based oxides (Mnoxides) synthesized using plasma-based methods are explored as non-toxic absorber nanomaterials for solar cells. N-CQDs are synthesized with varying synthesis parameters and precursors to increase the absorption window towards the visible region. Insights into the observed photoluminescence and its relationship with nitrogen doping is studied in detail along with absorption and electronic properties. Proof of concept solar cell devices are fabricated by using these N-CQDs as absorbers. Nitrogen doping in the N-CQDs is unable to significantly increase the visible-region absorption and thus limits the applicability as absorbers. Mn-oxides are explored as absorbers pertaining to their high absorption in the visible-region. A novel approach is followed for the synthesis which results in mixed phase oxyhydroxides with nanowires and sheet-like morphology. The effect of discharge current applied through the plasma-liquid interface during the synthesis process is studied as a parameter to tailor morphology, crystallinity and size of the nanostructures. The properties of the synthesized nanostructures are studied in detail and the results show that Mn-oxides could offer great opportunities as absorbers in solar cells.
Date of AwardFeb 2022
Original languageEnglish
SponsorsDepartment for the Economy
SupervisorPaul Maguire (Supervisor) & Davide Mariotti (Supervisor)


  • Carbon quantum dots
  • Manganese oxyhydroxides
  • Absorbers
  • Atmospheric pressure microplasma

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