Abstract
AbstractCesium‐based inorganic perovskites have recently attracted great research focus due to their excellent optoelectronic properties and thermal stability. However, the operational instability of all‐inorganic perovskites is still a main hindrance for the commercialization. Herein, a facile approach is reported to simultaneously enhance both the efficiency and long‐term stability for all‐inorganic CsPbI2.5Br0.5 perovskite solar cells via inducing excess lead iodide (PbI2) into the precursors. Comprehensive film and device characterizations are conducted to study the influences of excess PbI2 on the crystal quality, passivation effect, charge dynamics, and photovoltaic performance. It is found that excess PbI2 improves the crystallization process, producing high‐quality CsPbI2.5Br0.5 films with enlarged grain sizes, enhanced crystal orientation, and unchanged phase composition. The residual PbI2 at the grain boundaries also provides a passivation effect, which improves the optoelectronic properties and charge collection property in optimized devices, leading to a power conversion efficiency up to 17.1% with a high open‐circuit voltage of 1.25 V. More importantly, a remarkable long‐term operational stability is also achieved for the optimized CsPbI2.5Br0.5 solar cells, with less than 24% degradation drop at the maximum power point under continuous illumination for 420 h.
Highlights
The operational instability of all-inorganic perovskites is still a main hindrance for the commercialization
The perovskite films were deposited by the one-step spin-coating method from the precursor with a recipe of x mmol PbI2 (x = 1.00, 1.02, 1.04, 1.06), 0.5 mmol CsBr, and 0.5 mmol CsI in a mixture solvent of dimethyl sulfoxide (DMSO) and dimethylformamide (DMF)
The significantly improved champion PCE with a low VOC-deficits of 0.57 V demonstrates the effectiveness of excess PbI2 in fabricating high-efficiency all-inorganic PSCs
Summary
The operational instability of all-inorganic perovskites is still a main hindrance for the commercialization. A facile approach is reported to simultaneously enhance both the efficiency and long-term stability for allinorganic CsPbI2.5Br0.5 perovskite solar cells via inducing excess lead iodide (PbI2) into the precursors. It is found that excess PbI2 improves the crystallization process, producing high-quality CsPbI2.5Br0.5 films with enlarged grain sizes, enhanced crystal orientation, and unchanged phase composition. Based PSCs, which are more robust under provides a passivation effect, which improves the optoelectronic properties thermal stress, have gained increased and charge collection property in optimized devices, leading to a power conversion efficiency up to 17.1% with a high open-circuit voltage of 1.25 V. A remarkable long-term operational stability is achieved for the optimized CsPbI2.5Br0.5 solar cells, with less than 24% degradation drop at research interest.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
