Electronic Materials Letters

, Volume 15, Issue 2, pp 192–200 | Cite as

Uniform Cs2SnI6 Thin Films for Lead-Free and Stable Perovskite Optoelectronics via Hybrid Deposition Approaches

  • Byungho Lee
  • Byungha ShinEmail author
  • Byungwoo ParkEmail author
Original Article - Energy and Sustainability


Herein, we synthesized uniform Cs2SnI6 films by two kinds of hybrid deposition methods by considering volume expansion involved during phase transformations. First, oblique thermal evaporation for CsI followed by SnI4 spin-coating resulted in uniform Cs2SnI6 films free of impurity phases. The rapid expansion (within 10 s of spin-coating) from CsI to Cs2SnI6\((\Delta V = 106\% )\) was accommodated by porous CsI films inhibiting crack formation. Excess SnI4 on the Cs2SnI6 after spin-coating was effectively removed by toluene washing without any damages to Cs2SnI6, and optimum deposition parameters were suggested in terms of carrier mobility. Second, annealing CsI with SnI4 vapor at 250 °C and post-annealing in the SnI4 and I2 vapor at 300 °C produced Cs2SnI6 film with complete coverage. The slow reaction (70 min for a complete conversion) provided sufficient time for complete diffusion of SnI4 into CsI without crack formation even with compact CsI. The nonradiative recombination path in Cs2SnI6 was suppressed by post-annealing in the SnI4- and I2-atmosphere, as confirmed from the enhanced photoluminescence.

Graphical Abstract


Lead-free perovskite Cs2SnI6 Oblique thermal deposition Electrical mobility 



This work is supported by the National Research Foundation of Korea (NRF: 2016R1A2B4012938) and Korea Institute of Energy Technology Evaluation and Planning (KETEP: 20183010014470).


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Copyright information

© The Korean Institute of Metals and Materials 2019

Authors and Affiliations

  1. 1.Department of Materials Science and Engineering, Research Institute of Advanced MaterialsSeoul National UniversitySeoulKorea
  2. 2.Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeonKorea

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