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Mixed AgBiS 2 nanocrystals for photovoltaics and photodetectors.

Ignasi Burgués-CeballosYongjie WangGerasimos Konstantatos
Published in: Nanoscale (2022)
Heavy-metal-free colloidal nanocrystals are gaining due attention as low-cost, semiconducting materials for solution-processed optoelectronic applications. One common limitation of such materials is their limited carrier transport and trap-assisted recombination, which impede the performance of thick photoactive layers. Here we mix small-size and large-size AgBiS 2 nanocrystals to judiciously favour the band alignment in photovoltaic and photodetector devices. The absorbing layer of these devices is fabricated in a gradient fashion in order to maximise charge transfer and transport. We implement this strategy to fabricate mixed AgBiS 2 thin film solar cells with a power conversion of 7.3%, which significantly surpasses the performance of previously reported devices based on single-batch AgBiS 2 nanocrystals. Additionally, this approach allows us to fabricate devices using thicker photoactive layers that show lower dark currents and external quantum efficiencies exceeding 40% over a broad bandwidth - covering the visible and near infrared range beyond 1 μm, thus unleashing the potential of colloidal AgBiS 2 nanocrystals in photodetector applications.
Keyphrases
  • solar cells
  • energy transfer
  • room temperature
  • low cost
  • dna damage
  • working memory
  • dna repair
  • molecular dynamics
  • climate change
  • oxidative stress