Benzylamine-Treated Wide-Bandgap Perovskite with High Thermal-Photostability and Photovoltaic Performance

Yang Zhou, Feng Wang, Yu Cao, Jian-Pu Wang, Hong-Hua Fang, Maria Antonietta Loi, Ni Zhao, Ching-Ping Wong

Research output: Contribution to journalArticleAcademicpeer-review

89 Citations (Scopus)

Abstract

Mixed iodide-bromide organolead perovskites with a bandgap of 1.70-1.80 eV have great potential to boost the efficiency of current silicon solar cells by forming a perovskite-silicon tandem structure. Yet, the stability of the perovskites under various application conditions, and in particular combined light and heat stress, is not well studied. Here, FA(0.15)Cs(0.85)Pb(I0.73Br0.27)(3), with an optical bandgap of approximate to 1.72 eV, is used as a model system to investigate the thermal-photostability of wide-bandgap mixed halide perovskites. It is found that the concerted effect of heat and light can induce both phase segregation and decomposition in a pristine perovskite film. On the other hand, through a postdeposition film treatment with benzylamine (BA) molecules, the highly defective regions (e.g., film surface and grain boundaries) of the film can be well passivated, thus preventing the progression of decomposition or phase segregation in the film. Besides the stability improvement, the BA-modified perovskite solar cells also exhibit excellent photovoltaic performance, with the champion device reaching a power conversion efficiency of 18.1%, a stabilized power output efficiency of 17.1% and an open-circuit voltage (V-oc) of 1.24 V.

Original languageEnglish
Article number1701048
Number of pages7
JournalAdvanced Energy Materials
Volume7
Issue number22
DOIs
Publication statusPublished - 22-Nov-2017

Keywords

  • passivation
  • photostability
  • solar cells
  • thermal stability
  • wide-bandgap perovskites
  • HETEROJUNCTION SOLAR-CELLS
  • EFFICIENT
  • LEAD

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