skip to main content


This content will become publicly available on March 29, 2018

Title: Defect-induced band-edge reconstruction of a bismuth-halide double perovskite for visible-light absorption

In this study, halide double perovskites have recently been developed as less toxic analogs of the lead perovskite solar-cell absorbers APbX 3 (A = monovalent cation; X = Br or I). However, all known halide double perovskites have large bandgaps that afford weak visible-light absorption. The first halide double perovskite evaluated as an absorber, Cs 2AgBiBr 6 (1), has a bandgap of 1.95 eV. Here, we show that dilute alloying decreases 1’s bandgap by ca. 0.5 eV. Importantly, time-resolved photoconductivity measurements reveal long-lived carriers with microsecond lifetimes in the alloyed material, which is very promising for photovoltaic applications. The alloyed perovskite described herein is the first double perovskite to show comparable bandgap energy and carrier lifetime to those of (CH 3NH 3)PbI 3. By describing how energy- and symmetry-matched impurity orbitals, at low concentrations, dramatically alter 1’s band edges, we open a potential pathway for the large and diverse family of halide double perovskites to compete with APbX 3 absorbers.
 [1] ;  [2] ;  [3] ;  [4] ; ORCiD logo [5] ;  [6] ;  [7] ; ORCiD logo [1]
  1. Stanford Univ., Stanford, CA (United States)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
  3. Delft Univ. of Technology, Delft (The Netherlands); Materials Innovation Institute (M2i), Delft (The Netherlands)
  4. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
  5. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  6. Delft Univ. of Technology, Delft (The Netherlands)
  7. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Kavli Energy NanoScience, Berkeley, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-76SF00515; AC02-05CH11231; DGE-1147470; F71.4.15562a
Accepted Manuscript
Journal Name:
Journal of the American Chemical Society
Additional Journal Information:
Journal Volume: 139; Journal Issue: 14; Journal ID: ISSN 0002-7863
American Chemical Society (ACS)
Research Org:
SLAC National Accelerator Lab. (SLAC), Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
OSTI Identifier: