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Title: Bandgap Engineering of Lead-Free Double Perovskite Cs 2 AgBiBr 6 through Trivalent Metal Alloying

Authors:
 [1];  [2];  [2];  [2]; ORCiD logo [1]
  1. Department of Mechanical Engineering and Materials Science, and Department of Chemistry, Duke University, Box 90300 Hudson Hall Durham NC 27708-0300 USA
  2. Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, The University of Toledo, Toledo OH 43606 USA
Publication Date:
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
OSTI Identifier:
1401904
Grant/Contract Number:
EE0006712
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Angewandte Chemie (International Edition)
Additional Journal Information:
Journal Name: Angewandte Chemie (International Edition); Journal Volume: 56; Journal Issue: 28; Related Information: CHORUS Timestamp: 2017-10-20 18:08:08; Journal ID: ISSN 1433-7851
Publisher:
Wiley Blackwell (John Wiley & Sons)
Country of Publication:
Germany
Language:
English

Citation Formats

Du, Ke-zhao, Meng, Weiwei, Wang, Xiaoming, Yan, Yanfa, and Mitzi, David B. Bandgap Engineering of Lead-Free Double Perovskite Cs 2 AgBiBr 6 through Trivalent Metal Alloying. Germany: N. p., 2017. Web. doi:10.1002/anie.201703970.
Du, Ke-zhao, Meng, Weiwei, Wang, Xiaoming, Yan, Yanfa, & Mitzi, David B. Bandgap Engineering of Lead-Free Double Perovskite Cs 2 AgBiBr 6 through Trivalent Metal Alloying. Germany. doi:10.1002/anie.201703970.
Du, Ke-zhao, Meng, Weiwei, Wang, Xiaoming, Yan, Yanfa, and Mitzi, David B. Mon . "Bandgap Engineering of Lead-Free Double Perovskite Cs 2 AgBiBr 6 through Trivalent Metal Alloying". Germany. doi:10.1002/anie.201703970.
@article{osti_1401904,
title = {Bandgap Engineering of Lead-Free Double Perovskite Cs 2 AgBiBr 6 through Trivalent Metal Alloying},
author = {Du, Ke-zhao and Meng, Weiwei and Wang, Xiaoming and Yan, Yanfa and Mitzi, David B.},
abstractNote = {},
doi = {10.1002/anie.201703970},
journal = {Angewandte Chemie (International Edition)},
number = 28,
volume = 56,
place = {Germany},
year = {Mon Jun 12 00:00:00 EDT 2017},
month = {Mon Jun 12 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on June 12, 2018
Publisher's Accepted Manuscript

Citation Metrics:
Cited by: 14works
Citation information provided by
Web of Science

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  • Novel inorganic lead-free double perovskites with improved stability are regarded as alternatives to state-of-art hybrid lead halide perovskites in photovoltaic devices. The recently discovered Cs2AgBiBr6 double perovskite exhibits attractive optical and electronic features, making it promising for various optoelectronic applications. However, its practical performance is hampered by the large band gap. In this work, remarkable band gap narrowing of Cs2AgBiBr6 is, for the first time, achieved on inorganic photovoltaic double perovskites through high pressure treatments. Moreover, the narrowed band gap is partially retainable after releasing pressure, promoting its optoelectronic applications. This work not only provides novel insights into the structure–propertymore » relationship in lead-free double perovskites, but also offers new strategies for further development of advanced perovskite devices.« less
  • Cited by 23
  • Vacancy-ordered double perovskites of the general formula, A2BX6, are a family of perovskite derivatives composed of a face-centered lattice of nearly isolated [BX6] units with A-site cations occupying the cuboctahedral voids. Despite the presence of isolated octahedral units, the close-packed iodide lattice provides significant electronic dispersion, such that Cs2SnI6 has recently been explored for applications in photovoltaic devices. To elucidate the structure-property relationships of these materials, we have synthesized the solid solution Cs2Sn1-xTexI6. However, even though tellurium substitution increases electronic dispersion via closer I-I contact distances, the substitution experimentally yields insulating behavior from a significant decrease in carrier concentration andmore » mobility. Density functional calculations of native defects in Cs2SnI6 reveal that iodine vacancies exhibit a low enthalpy of formation and the defect energy level is a shallow donor to the conduction band, rendering the material tolerant to these defect states. The increased covalency of Te-I bonding renders the formation of iodine vacancy states unfavorable, and is responsible for the reduction in conductivity upon Te substitution. Additionally, Cs2TeI6 is intolerant to the formation of these defects, as the defect level occurs deep within the band gap and thus localizes potential mobile charge carriers. In these vacancy-ordered double perovskites, the close-packed lattice of iodine provides significant electronic dispersion, while the interaction of the B- and X-site ions dictates the properties as they pertain to electronic structure and defect tolerance. This simplified perspective -- based on extensive experimental and theoretical analysis -- provides a platform from which to understand structure-property relationships in functional perovskite halides.« less