TY - JOUR
T1 - Defect-Induced Band-Edge Reconstruction of a Bismuth-Halide Double Perovskite for Visible-Light Absorption
AU - Slavney, Adam H.
AU - Leppert, Linn
AU - Bartesaghi, Davide
AU - Gold-Parker, Aryeh
AU - Toney, Michael F.
AU - Savenije, Tom J.
AU - Neaton, Jeffrey B.
AU - Karunadasa, Hemamala I.
PY - 2017/4/12
Y1 - 2017/4/12
N2 - 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 2 AgBiBr 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 3 NH 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.
AB - 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 2 AgBiBr 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 3 NH 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.
UR - http://www.scopus.com/inward/record.url?scp=85018365492&partnerID=8YFLogxK
U2 - 10.1021/jacs.7b01629
DO - 10.1021/jacs.7b01629
M3 - Article
C2 - 28353345
AN - SCOPUS:85018365492
SN - 0002-7863
VL - 139
SP - 5015
EP - 5018
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 14
ER -
