Two-step growth of CsPbI3−xBrx films employing dynamic CsBr treatment: toward all-inorganic perovskite photovoltaics with enhanced stability

Recently, CsPbI3−xBrx (x = 1–2) all-inorganic perovskites have been studied to overcome the phase instability of CsPbI3. However, the addition of Br inevitably leads to a bandgap that is too wide (1.93–2.03 eV) compared to that of CsPbI3 (1.73 eV). To avoid this, the present study focuses on develop...

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Bibliographic Details
Published in:Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2019, Vol.7 (31), p.18488-18498
Main Authors: Parida, Bhaskar, Ryu, Jun, Yoon, Saemon, Lee, Seojun, Seo, Yejin, Cho, Jung Sang, Dong-Won, Kang
Format: Article
Language:English
Subjects:
Cesium bromides
Dynamic stability
Energy conversion efficiency
Energy gap
Fabrication
Mathematical morphology
Optical properties
Perovskites
Photovoltaic cells
Photovoltaics
Solar cells
Stability
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Summary:Recently, CsPbI3−xBrx (x = 1–2) all-inorganic perovskites have been studied to overcome the phase instability of CsPbI3. However, the addition of Br inevitably leads to a bandgap that is too wide (1.93–2.03 eV) compared to that of CsPbI3 (1.73 eV). To avoid this, the present study focuses on developing stable α-CsPbI3−xBrx (x < 0.7) perovskite films with lower Br levels. Our dynamic CsBr treatment incorporates Br− into the CsPbI3 lattice, greatly enhancing the morphology, optical properties, stability, and photovoltaic performance of the resultant CsPbI3−xBrx (x < 0.7) perovskite films. At x = 0.66, the perovskite film with the relatively low bandgap of 1.84 eV contributes to achieving an impressive power conversion efficiency (PCE) of 14.08% and, after 1200 h storage under a nitrogen atmosphere without encapsulation, the PCE remains at around 70% of this initial level. This two-step growth using dynamic CsBr treatment opens up promising routes for the feasible fabrication of inorganic perovskite photovoltaics with exceptional stability.
ISSN:2050-7488
2050-7496
DOI:10.1039/c9ta05948b