Lead-Free Double Perovskite Cs2 SnX6 : Facile Solution Synthesis and Excellent Stability

Xiao Han; Jia Liang; Ji-Hui Yang; Khushboo Soni; Qiyi Fang; Weipeng Wang; Jing Zhang; Shuai Jia; Angel A Martí; Yan Zhao; Jun Lou

doi:10.1002/smll.201901650

Lead-Free Double Perovskite Cs₂ SnX₆ : Facile Solution Synthesis and Excellent Stability

Small. 2019 Sep;15(39):e1901650. doi: 10.1002/smll.201901650. Epub 2019 Aug 2.

Authors

Xiao Han^{1

2

3}, Jia Liang^{2

4}, Ji-Hui Yang⁵, Khushboo Soni^{2

6}, Qiyi Fang², Weipeng Wang², Jing Zhang², Shuai Jia², Angel A Martí^{4

7}, Yan Zhao³, Jun Lou^{2

4

7}

Affiliations

¹ School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, 710072, China.
² Department of Materials Science and NanoEngineering, Rice University, 6100 Main Street, Houston, TX, 77005, USA.
³ School of Materials Science and Engineering, Beihang University, Beijing, 100191, China.
⁴ Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, TX, 77005, USA.
⁵ Department of Physics, Key Laboratory for Computational Science (MOE), State Key Laboratory of Surface Physics, Fudan University, Shanghai, 200433, China.
⁶ Institute of Nano-Science and Technology, Habitat Centre, Phase-10, Sector-64, Mohali, 160062, India.
⁷ Department of Chemistry, Rice University, 6100 Main Street, Houston, TX, 77005, USA.

PMID: 31373741
DOI: 10.1002/smll.201901650

Abstract

Long-term instability and possible lead contamination are the two main issues limiting the widespread application of organic-inorganic lead halide perovskites. Here a facile and efficient solution-phase method is demonstrated to synthesize lead-free Cs₂ SnX₆ (X = Br, I) with a well-defined crystal structure, long-term stability, and high yield. Based on the systematic experimental data and first-principle simulation results, Cs₂ SnX₆ displays excellent stability against moisture, light, and high temperature, which can be ascribed to the unique vacancy-ordered defect-variant structure, stable chemical compositions with Sn⁴⁺ , as well as the lower formation enthalpy for Cs₂ SnX₆ . Additionally, photodetectors based on Cs₂ SnI₆ are also fabricated, which show excellent performance and stability. This study provides very useful insights into the development of lead-free double perovskites with high stability.

Keywords: Cs2SnI6; double perovskites; lead-free; photodetectors; solution synthesis; stability.

Abstract

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