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Unveiling Double A-Site Cation Perovskite-Inspired Materials : From 0D-Cs3Bi2I9 to 2D-Cs2AgBi2I9 with Enhanced Charge Transport
Publikationstyp
Journal Article
Publikationsdatum
2024-08-09
Sprache
English
Author
Hossain, Mozakkar
Singh, Kuntal
Narwal, Ankita
Sheikh, Md Sariful
Reddy, Sandeep K.
Vankayala, Kiran
Singh, Asha
Khan, Saleem
Khan, Salahuddin
Velpula, Praveen Kumar
Chirumamilla, Manohar
Yamijala, Sharma S.R.K.C.
Grandhi, G. Krishnamurthy
Vivo, Paola
Rao, K. D.M.
Enthalten in
Volume
36
Issue
16
Start Page
7781
End Page
7791
Citation
Chemistry of Materials 36 (16): 7781-7791 (2024-08-09)
Publisher DOI
Scopus ID
Publisher
American Chemical Society
Bismuth-based halideperovskite-inspired materials (PIMs) are gaining increasing attention as sustainable and stable alternatives to lead halide perovskites. However, many PIMs have wide band gaps (≥2 eV) and low electronic dimensionality, limiting their utility in optoelectronic applications. In this study, we introduce Cs2AgBi2I9, a two-dimensional perovskite-inspired absorber achieved through partial substitution of Cs+ with Ag+ at the A-site of Cs3Bi2I9. Single-crystal X-ray diffraction analysis reveals that silver atoms occupy the edge sites in the hexagonal lattice, resulting in contracted lattice parameters compared to the parent Cs3Bi2I9. The double A-cation substitution promotes orbital overlap between Ag 5s and I 6p orbitals, leading to a narrower band gap of 1.72 eV and a delocalized electronic structure in Cs2AgBi2I9. Consequently, the 2D-PIM exhibits a three-orders-of-magnitude lower electrical resistivity and an exceptional carrier mobility-lifetime product (μτ) of 3.4 × 10-3 cm2 V-1, representing the highest among solution-processed Bi-PIMs. Furthermore, low-temperature photoluminescence measurements indicate weak electron-phonon coupling, while transient absorption spectroscopy reveals extended hot-carrier lifetimes, suggesting efficient exciton transport in Cs2AgBi2I9. Utilizing these exceptional charge transport properties, Cs2AgBi2I9 photodetectors show a remarkable broad spectral response. This work demonstrates the potential of a double A-site cation engineering strategy to develop low-toxicity PIMs with precisely tailored structural and optoelectronic properties.
DDC Class
621.3: Electrical Engineering, Electronic Engineering
660.2: Chemical Engineering