Band-Like Charge Transport in Cs₂AgBiBr₆ and Mixed Antimony-Bismuth Cs₂AgBi_{1- x}Sb_xBr₆ Halide Double Perovskites

Band-Like Charge Transport in Cs₂AgBiBr₆ and Mixed Antimony-Bismuth Cs₂AgBi_{1- x}Sb_xBr₆ Halide Double Perovskites

Hutter, E.M. (TU Delft ChemE/Opto-electronic Materials; Stanford University)
Gelvez Rueda, M.C. (TU Delft ChemE/Opto-electronic Materials)
Bartesaghi, D. (TU Delft ChemE/Opto-electronic Materials)
Grozema, F.C. (TU Delft ChemE/Opto-electronic Materials)
Savenije, T.J. (TU Delft ChemE/Opto-electronic Materials)

2018

Recently, halide double perovskites (HDPs), such as Cs₂AgBiBr₆, have been reported as promising nontoxic alternatives to lead halide perovskites. However, it remains unclear whether the charge-transport properties of these materials are as favorable as for lead-based perovskites. In this work, we study the mobilities of charges in Cs₂AgBiBr₆ and in mixed antimony-bismuth Cs₂AgBi_1-xSb_xBr₆, in which the band gap is tunable from 2.0 to 1.6 eV. Using temperature-dependent time-resolved microwave conductivity techniques, we find that the mobility is proportional to T^-p (with p ≈ 1.5). Importantly, this indicates that phonon scattering is the dominant scattering mechanism determining the charge carrier mobility in these HDPs similar to the state-of-the-art lead-based perovskites. Finally, we show that wet chemical processing of Cs₂AgBi_1-xSb_xBr₆ powders is a successful route to prepare thin films of these materials, which paves the way toward photovoltaic devices based on nontoxic HDPs with tunable band gaps.

http://resolver.tudelft.nl/uuid:01f76f25-ecec-454e-a457-10cd45aa4408

https://doi.org/10.1021/acsomega.8b01705

0305-0483

Omega, 3 (9), 11655-11662

Institutional Repository

journal article

© 2018 E.M. Hutter, M.C. Gelvez Rueda, D. Bartesaghi, F.C. Grozema, T.J. Savenije