Stabilization of Component-Pure α-FAPbI3 via Volatile Additives for Stable Photovoltaics

Dianxi Wang, Muyang Chen, Xuecong Zhang, Lingfeng Chao, Tingting Niu, Yifan Lv, Guichuan Xing, Yingdong Xia, Mingjie Li, Hui Zhang, Yonghua Chen

Research output: Journal article publicationJournal articleAcademic researchpeer-review

5 Citations (Scopus)

Abstract

State-of-the-art high-performance perovskite solar cells are mainly based on formamidinium (FA)-dominated perovskites because of their narrow band gap and remarkable thermal resistance. However, photoactive α-FAPbI3 is prone to transit to the photoinactive phase, and pioneering phase stabilization strategies can induce undesirable band gap broadening or phase segregation, seriously restricting the efficiency and long-term stability of the resultant photovoltaics. Herein, a small molecule of ammonium acetate (NH4Ac) was introduced as an additive in a modified ripening method to fabricate component-pure α-FAPbI3. Owing to the strong interaction between NH4Ac and PbI2, FAI via Pb-O coordination, and N-H···N hydrogen bonding, vertically oriented perovskites with relaxed crystal strain were first generated, which were fully converted to α-FAPbI3 in a further ripening process. The NH4Ac was fully volatized after the perovskite formation, resulting in component-pure α-FAPbI3 with a band gap of 1.48 eV and remarkable stability under light illumination. Ultimately, a champion device efficiency of above 21% was obtained based on the component-pure α-FAPbI3 and over 95% of the initial efficiency can be maintained after 1000 h of aging.

Original languageEnglish
Pages (from-to)16818-16827
Number of pages10
JournalACS Applied Materials and Interfaces
Volume15
Issue number13
DOIs
Publication statusPublished - Mar 2023

Keywords

  • ammonium acetate
  • perovskite solar cells
  • phase stability
  • volatile additives
  • α-FAPbI

ASJC Scopus subject areas

  • General Materials Science

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