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Title: Stable Formamidinium-Based Perovskite Solar Cells via In Situ Grain Encapsulation

Formamidinium (FA)-based lead iodide perovskites have emerged as the most promising light-absorber materials in the prevailing perovskite solar cells (PSCs). However, they suffer from the phase-instability issue in the ambient atmosphere, which is holding back the realization of the full potential of FA-based PSCs in the context of high efficiency and stability. Herein, the tetraethylorthosilicate hydrolysis process is integrated with the solution crystallization of FA-based perovskites, forming a new film structure with individual perovskite grains encapsulated by amorphous silica layers that are in situ formed at the nanoscale. The silica not only protects perovskite grains from the degradation but also enhances the charge-carrier dynamics of perovskite films. The underlying mechanism is discussed using a joint experiment-theory approach. Through this in situ grain encapsulation method, PSCs show an efficiency close to 20% with an impressive 97% retention after 1000-h storage under ambient conditions.
 [1] ;  [2] ;  [3] ;  [2] ;  [4] ;  [1] ;  [5] ;  [5] ;  [5] ;  [1] ;  [2] ;  [5] ;  [4] ;  [5] ;  [6] ; ORCiD logo [6]
  1. Peking Univ., Beijing (China)
  2. Brown Univ., Providence, RI (United States)
  3. National Renewable Energy Lab. (NREL), Golden, CO (United States); Northwestern Polytechnical Univ., Xi'an (China)
  4. Univ. of Nebraska, Lincoln, NE (United States)
  5. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  6. Peking Univ., Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Shanxi Univ. (China)
Publication Date:
Report Number(s):
Journal ID: ISSN 1614-6832
Grant/Contract Number:
AC36-08GO28308; AC36-08-GO28308
Accepted Manuscript
Journal Name:
Advanced Energy Materials
Additional Journal Information:
Journal Volume: 8; Journal Issue: 22; Journal ID: ISSN 1614-6832
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; charge transport; encapsulate; perovskite; silica; stability
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1439768