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Title: Small-Band-Gap Halide Double Perovskites

Despite their compositional versatility, most halide double perovskites feature large band gaps. Herein, we describe a strategy for achieving small band gaps in this family of materials. The new double perovskites Cs 2AgTlX 6 (X=Cl (1) and Br (2)) have direct band gaps of 2.0 and 0.95 eV, respectively, which are approximately 1 eV lower than those of analogous perovskites. To our knowledge, compound 2 displays the lowest band gap for any known halide perovskite. Unlike in A IB IIX 3 perovskites, the band–gap transition in A I 2BB'X 6 double perovskites can show substantial metal–to–metal charge–transfer character. This band–edge orbital composition is used to achieve small band gaps through the selection of energetically aligned B– and B'–site metal frontier orbitals. Calculations reveal a shallow, symmetry–forbidden region at the band edges for 1, which results in long (μs) microwave conductivity lifetimes. In conclusion, we further describe a facile self–doping reaction in 2 through Br 2 loss at ambient conditions.
Authors:
ORCiD logo [1] ; ORCiD logo [2] ;  [1] ; ORCiD logo [3] ; ORCiD logo [4] ; ORCiD logo [5] ; ORCiD logo [1]
  1. Stanford Univ., Stanford, CA (United States)
  2. Univ. of Bayreuth, Bayreuth (Germany)
  3. Delft Univ. of Technology, Delft (Netherlands); Materials Innovation Institute, Delft (Netherlands)
  4. Delft Univ. of Technology, Delft (Netherlands)
  5. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kavli Energy NanoScience, Berkeley, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-76SF00515; DMR-1708892; ECCS-1542152
Type:
Accepted Manuscript
Journal Name:
Angewandte Chemie (International Edition)
Additional Journal Information:
Journal Name: Angewandte Chemie (International Edition); Journal Volume: 57; Journal Issue: 39; Journal ID: ISSN 1433-7851
Publisher:
Wiley
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; absorber; band gap; band structure; doping; halide double perovskite
OSTI Identifier:
1475457
Alternate Identifier(s):
OSTI ID: 1467925

Slavney, Adam H., Leppert, Linn, Valdes, Abraham Saldivar, Bartesaghi, Davide, Savenije, Tom J., Neaton, Jeffrey B., and Karunadasa, Hemamala I.. Small-Band-Gap Halide Double Perovskites. United States: N. p., Web. doi:10.1002/anie.201807421.
Slavney, Adam H., Leppert, Linn, Valdes, Abraham Saldivar, Bartesaghi, Davide, Savenije, Tom J., Neaton, Jeffrey B., & Karunadasa, Hemamala I.. Small-Band-Gap Halide Double Perovskites. United States. doi:10.1002/anie.201807421.
Slavney, Adam H., Leppert, Linn, Valdes, Abraham Saldivar, Bartesaghi, Davide, Savenije, Tom J., Neaton, Jeffrey B., and Karunadasa, Hemamala I.. 2018. "Small-Band-Gap Halide Double Perovskites". United States. doi:10.1002/anie.201807421.
@article{osti_1475457,
title = {Small-Band-Gap Halide Double Perovskites},
author = {Slavney, Adam H. and Leppert, Linn and Valdes, Abraham Saldivar and Bartesaghi, Davide and Savenije, Tom J. and Neaton, Jeffrey B. and Karunadasa, Hemamala I.},
abstractNote = {Despite their compositional versatility, most halide double perovskites feature large band gaps. Herein, we describe a strategy for achieving small band gaps in this family of materials. The new double perovskites Cs2AgTlX6 (X=Cl (1) and Br (2)) have direct band gaps of 2.0 and 0.95 eV, respectively, which are approximately 1 eV lower than those of analogous perovskites. To our knowledge, compound 2 displays the lowest band gap for any known halide perovskite. Unlike in AIBIIX3 perovskites, the band–gap transition in AI2BB'X6 double perovskites can show substantial metal–to–metal charge–transfer character. This band–edge orbital composition is used to achieve small band gaps through the selection of energetically aligned B– and B'–site metal frontier orbitals. Calculations reveal a shallow, symmetry–forbidden region at the band edges for 1, which results in long (μs) microwave conductivity lifetimes. In conclusion, we further describe a facile self–doping reaction in 2 through Br2 loss at ambient conditions.},
doi = {10.1002/anie.201807421},
journal = {Angewandte Chemie (International Edition)},
number = 39,
volume = 57,
place = {United States},
year = {2018},
month = {8}
}

Works referenced in this record:

Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells
journal, May 2009
  • Kojima, Akihiro; Teshima, Kenjiro; Shirai, Yasuo
  • Journal of the American Chemical Society, Vol. 131, Issue 17, p. 6050-6051
  • DOI: 10.1021/ja809598r

Detailed Balance Limit of Efficiency of p‐n Junction Solar Cells
journal, March 1961
  • Shockley, William; Queisser, Hans J.
  • Journal of Applied Physics, Vol. 32, Issue 3, p. 510-519
  • DOI: 10.1063/1.1736034

Semiconducting Tin and Lead Iodide Perovskites with Organic Cations: Phase Transitions, High Mobilities, and Near-Infrared Photoluminescent Properties
journal, July 2013
  • Stoumpos, Constantinos C.; Malliakas, Christos D.; Kanatzidis, Mercouri G.
  • Inorganic Chemistry, Vol. 52, Issue 15, p. 9019-9038
  • DOI: 10.1021/ic401215x

Air-Stable Molecular Semiconducting Iodosalts for Solar Cell Applications: Cs2SnI6 as a Hole Conductor
journal, October 2014
  • Lee, Byunghong; Stoumpos, Constantinos C.; Zhou, Nanjia
  • Journal of the American Chemical Society, Vol. 136, Issue 43, p. 15379-15385
  • DOI: 10.1021/ja508464w