Nucleation Regulation and Mesoscopic Dielectric Screening in α-FAPbI3

Ruijia Tian, Chang Liu, Yuanyuan Meng, Yaohua Wang, Ruikun Cao, Bencan Tang, Darren Walsh, Hainam Do, Haodong Wu, Kai Wang, Kexuan Sun, Shuncheng Yang, Jintao Zhu, Xin Li, Ziyi Ge

Research output: Journal PublicationArticlepeer-review

Abstract

While significant advancements in power conversion efficiencies (PCEs) of α-FAPbI3perovskite solar cells (PSCs) have been made, attaining controllable perovskite crystallization is still a considerable hurdle. This challenge stems from the initial formation of δ-FAPbI3, a more energetically stable phase than the desired black α-phase, during film deposition. This disrupts the heterogeneous nucleation of α-FAPbI3, causing the formation of mixed phases and defects. To this end, polarity engineering using molecular additives, specifically ((methyl-sulfonyl)phenyl)ethylamines (MSPEs) are introduced. The findings reveal that the interaction of PbI2-MSPEs-FAI intermediates is enhanced with the increased polarity of MSPEs, which in turn expedites the nucleation of α-FAPbI3. This leads to the development of high-quality α-FAPbI3 films, characterized by vertical crystal orientation and reduced residual stresses. Additionally, the increased dipole moment of MSPE at perovskite grain boundaries attenuates Coulomb attractions among charged defects and screens carrier capture process, thereby diminishing non-radiative recombination. Utilizing these mechanisms, PSCs treated with highly polar 2-(4-MSPE) achieve an impressive PCE of 25.2% in small-area devices and 20.5% in large-area perovskite solar modules (PSMs) with an active area of 70 cm2. These results demonstrate the effectiveness of this strategy in achieving controllable crystallization of α-FAPbI3, paving the way for scalable-production of high-efficiency PSMs.

Original languageEnglish
Article number2309998
JournalAdvanced Materials
Volume36
Issue number13
DOIs
Publication statusPublished - 28 Mar 2024

Keywords

  • Dielectric screening
  • Nonradiative decay
  • Nucleation regulation
  • Perovskite solar modules
  • Polarity engineering

ASJC Scopus subject areas

  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering

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