Multichannel Interdiffusion Driven FASnI3 Film Formation Using Aqueous Hybrid Salt/Polymer Solutions toward Flexible Lead-Free Perovskite Solar Cells

Jun Xi, Zhaoxin Wu, Bo Jiao, Hua Dong, Chenxin Ran, Chengcheng Piao, Ting Lei, Tze Bin Song, Weijun Ke, Takamichi Yokoyama, Xun Hou, Mercouri G. Kanatzidis

Research output: Contribution to journalArticlepeer-review

81 Citations (Scopus)


Tin (Sn)-based perovskites are increasingly attractive because they offer lead-free alternatives in perovskite solar cells. However, depositing high-quality Sn-based perovskite films is still a challenge, particularly for low-temperature planar heterojunction (PHJ) devices. Here, a “multichannel interdiffusion” protocol is demonstrated by annealing stacked layers of aqueous solution deposited formamidinium iodide (FAI)/polymer layer followed with an evaporated SnI2 layer to create uniform FASnI3 films. In this protocol, tiny FAI crystals, significantly inhibited by the introduced polymer, can offer multiple interdiffusion pathways for complete reaction with SnI2. What is more, water, rather than traditional aprotic organic solvents, is used to dissolve the precursors. The best-performing FASnI3 PHJ solar cell assembled by this protocol exhibits a power conversion efficiency (PCE) of 3.98%. In addition, a flexible FASnI3-based flexible solar cell assembled on a polyethylene naphthalate–indium tin oxide flexible substrate with a PCE of 3.12% is demonstrated. This novel interdiffusion process can help to further boost the performance of lead-free Sn-based perovskites.

Original languageEnglish
Article number1606964
JournalAdvanced Materials
Issue number23
Publication statusPublished - Jun 20 2017


  • aqueous hybrid solutions
  • crystallization inhibitor
  • flexible devices
  • formamidinium tin iodide
  • multichannel interdiffusion

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Multichannel Interdiffusion Driven FASnI<sub>3</sub> Film Formation Using Aqueous Hybrid Salt/Polymer Solutions toward Flexible Lead-Free Perovskite Solar Cells'. Together they form a unique fingerprint.

Cite this