Probing the Stability and Band Gaps of Cs 2 AgInCl 6 and Cs 2 AgSbCl 6 Lead-Free Double Perovskite Nanocrystals

Dahl, Jakob C.; Osowiecki, Wojciech T.; Cai, Yao; Swabeck, Joseph K.; Bekenstein, Yehonadav; Asta, Mark; Chan, Emory M.; Alivisatos, A. Paul

doi:10.1021/acs.chemmater.8b04202

Title: Probing the Stability and Band Gaps of Cs ₂ AgInCl ₆ and Cs ₂ AgSbCl ₆ Lead-Free Double Perovskite Nanocrystals

Journal Article · Tue Apr 02 00:00:00 EDT 2019 · Chemistry of Materials

DOI:https://doi.org/10.1021/acs.chemmater.8b04202· OSTI ID:1542404

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Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
Univ. of California, Berkeley, CA (United States)
Univ. of California, Berkeley, CA (United States); Israel Inst. of Technology, Haifa (Israel)
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Lead toxicity has sparked interest into alternative halide nanomaterials with properties similar to CsPbX 3 perovskites. A promising alternative predicted from bulk studies is the family of double perovskites of the form Cs₂AgMX₆. In this work, we report the synthesis of colloidal CsCs₂AgInCl₆ and Cs₂AgSbCl₆ nanocrystals via injection of acyl halides into a metal acetate solution under atmospheric conditions and relatively mild temperatures. We reflect the synthesis of single-crystalline cubic nanocrystals of ca. 10 nm side length and their morphological similarities to other double perovskite nanostructures in terms of their [200] facet termination and decoration with Ag^(o) smaller nanocrystallites. To contrast the stabilities of the synthesized materials, we develop a titration assay based on the degradation of nanocrystals with amines as a proxy for degradation by humidity, which provides a quantifiable stability metric. This measurement shows that Cs₂AgSbCl₆ releases more than twice the decomposition energy compared to Cs₂ AgInCl₆ or CsPbCl₃ and degrades in the presence of approximately one molar equivalent of amine, whereas the other two materials require more than a 100-fold excess. Using facile chemical titration to quantitatively determine chemical stability provides an additional tool to aid in the basic understanding of what makes some of these materials more environmentally stable than others.

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Research Organization:: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; National Research Foundation of Korea (NRF)

Grant/Contract Number:: AC02-05CH11231

OSTI ID:: 1542404

Journal Information:: Chemistry of Materials, Vol. 31, Issue 9; ISSN 0897-4756

Publisher:: American Chemical Society (ACS)Copyright Statement

Country of Publication:: United States

Language:: English

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Cited by: 100 works

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Title: Probing the Stability and Band Gaps of Cs ₂ AgInCl ₆ and Cs ₂ AgSbCl ₆ Lead-Free Double Perovskite Nanocrystals