Mitigating Open-Circuit Voltage Loss in Pb-Sn Low-Bandgap Perovskite Solar Cells via Additive Engineering

Nabin Ghimire, Raja Sekhar Bobba, Ashim Gurung, Khan Mamun Reza, Md Ashiqur Rahman Laskar, Buddhi Sagar Lamsal, Khalid Emshadi, Rajesh Pathak, Mohammad Adil Afroz, Ashraful Haider Chowdhury, Ke Chen, Behzad Bahrami, Sheikh Ifatur Rahman, Jyotshna Pokharel, Abiral Baniya, Md Tawabur Rahman, Yue Zhou, Quinn Qiao

Research output: Contribution to journalArticlepeer-review

46 Scopus citations


Lead (Pb)-Tin (Sn) mixed perovskites suffer from large open-circuit voltage (Voc) loss due to the rapid crystallization of perovskite films, creating Sn and Pb vacancies. Such vacancies act as defect sites expediting charge carrier recombination, thus hampering the charge carrier dynamics and optoelectronic properties of the perovskite film. Here, we report the passivation of these defects using a controlled amount of 2-phenylethylazanium iodide (PEAI) in perovskite precursor solution as a dopant to enhance the performance of the 1.25 eV Pb-Sn low-bandgap perovskite solar cell. It was found that the incorporation of PEAI in the perovskite precursor not only improves the perovskite film quality and crystallinity but also lowers the electronic disorder, thereby enhancing the open-circuit voltage up to 0.85 V, corresponding to Voc loss as low as 0.4 V and the power conversion efficiency up to 17.33%. The value of Voc loss obtained with this strategy is among the least obtained for similar band gap Pb-Sn low-bandgap perovskite solar cells. Furthermore, the ambient and dark self-stability of the PEAI-treated devices were also enhanced. This work presents a simple doping strategy to mitigate the Voc loss of Pb-Sn mixed low-bandgap perovskite solar cells.

Original languageEnglish (US)
Pages (from-to)1731-1742
Number of pages12
JournalACS Applied Energy Materials
Issue number2
StatePublished - Feb 22 2021


  • PEAI salt
  • Pb-Sn hybrid perovskite
  • Vdeficit
  • additive engineering
  • defect passivation
  • low-bandgap perovskite

ASJC Scopus subject areas

  • Chemical Engineering (miscellaneous)
  • Energy Engineering and Power Technology
  • Materials Chemistry
  • Electrical and Electronic Engineering
  • Electrochemistry


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